Статті в журналах з теми "Shallow foundation system"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Shallow foundation system.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 статей у журналах для дослідження на тему "Shallow foundation system".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Leblouba, Moussa, Salah Al Toubat, Muhammad Ekhlasur Rahman, and Omer Mugheida. "Practical Soil-Shallow Foundation Model for Nonlinear Structural Analysis." Mathematical Problems in Engineering 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/4514152.
Анотація:
Soil-shallow foundation interaction models that are incorporated into most structural analysis programs generally lack accuracy and efficiency or neglect some aspects of foundation behavior. For instance, soil-shallow foundation systems have been observed to show both small and large loops under increasing amplitude load reversals. This paper presents a practical macroelement model for soil-shallow foundation system and its stability under simultaneous horizontal and vertical loads. The model comprises three spring elements: nonlinear horizontal, nonlinear rotational, and linear vertical springs. The proposed macroelement model was verified using experimental test results from large-scale model foundations subjected to small and large cyclic loading cases.
2
Naghibi, Farzaneh, and Gordon A. Fenton. "Target geotechnical reliability for redundant foundation systems." Canadian Geotechnical Journal 54, no. 7 (July 2017): 945–52. http://dx.doi.org/10.1139/cgj-2016-0478.
Анотація:
Geotechnical support systems (e.g., deep and shallow foundations) generally involve at least some redundancy. For example, if a building is supported by np separate foundations, then failure (e.g., excessive settlement) of a single foundation will generally not result in failure of the building if the building is able to shed the load from the failed foundation to adjacent foundations. This load-shedding ability lends the foundation system redundancy — system failure only occurs if multiple foundations fail. This paper investigates the relationship between the level of geotechnical redundancy, individual foundation reliability, and system reliability for deep foundations (piles). In the particular case where the pile resistance remains constant after achieving its ultimate capacity (at a certain displacement), the relationship between individual and system reliabilities is computed theoretically. The more general case, where the load carried by the pile reduces after exceeding its ultimate capacity, is investigated by Monte Carlo simulation. Charts relating system and individual reliability indices are presented, which can be used to aid in the design of individual piles as part of a pile support system.
3
Harden, Chad W., and Tara C. Hutchinson. "Beam-on-Nonlinear-Winkler-Foundation Modeling of Shallow, Rocking-Dominated Footings." Earthquake Spectra 25, no. 2 (May 2009): 277–300. http://dx.doi.org/10.1193/1.3110482.
Анотація:
The nonlinear behavior of shallow foundations under large amplitude earthquake-induced loading can result in dissipation of seismic energy through the mechanism of soil yielding beneath the foundation. In addition, foundation uplifting may shift the period of the soil-foundation-structure system away from the damaging energy content of most earthquakes. However, this yielding and uplifting may lead to excessive transient and permanent deformations (settlement, rocking, and sliding). Therefore, modeling procedures that account for foundation nonlinearity and uplift are needed before these benefits can be realized in performance based earthquake engineering (PBEE) practice. This paper adopts a beam-on-nonlinear-Winkler-foundation (BNWF) simulation methodology for modeling shallow foundation-structure systems, where seismically-induced rocking plays a predominant role in their response. Numerical results demonstrate that reasonable comparison between the nonlinear Winkler-based approach, and experimental response in terms of moment-rotation, settlement-rotation, and shear-sliding displacement can be obtained, given an appropriate selection of model and soil properties.
4
Sirat, Qurratu Aini, Dayangku Salma Awang Ismail, Azman Kassim, and Ahmad Safuan A. Rashid. "Application of distributed optical fibre for shallow foundation." MATEC Web of Conferences 250 (2018): 01019. http://dx.doi.org/10.1051/matecconf/201825001019.
Анотація:
Soil deformation is one of the major interests with regard to the stability analysis of the foundations. The deformations are signified for both vertical and lateral soil deformation; which the former plays vital role in designing a good foundation. As the stability of the foundation affect the stability of the entire structure, instrumentation and monitoring play an important roles in order to monitor the performances of the geotechnical structures. Until now the design of a foundation soil system is relied on the quantification of soil bearing capacity and foundation structural capacity and then followed by conventional monitoring system to observe the settlement so that within the allowable values. Therefore, this study focuses on the newly usage of distributed optical fibre sensing application to monitor strain distribution within a soil mass due to surcharge loading. It is expected to observe the strain distribution goes proportionally to vertical stress distribution concept; where higher strain measurement right below the loading position and decreases with depth. The advantage of distributed optical fibre sensing rather than conventional strain gauge is the sensor able to collect so-called average strain along the optical fibre compare to discrete measurement of strain gauge. This paper describes the experimental work conducted with the use of a distributed sensing technology named Brillouin Optical Time-Domain Analysis (BOTDA). A small scale of 1G model of a shallow foundation which represented by a load plate under incremental surcharge loading was stimulated to assess the soil mass deformation. The optical fibre were embedded in soil mass by layering in a horizontal direction which laid perpendicular to load direction. A comparison of numerical modeling using PLAXIS 2D and experimental works as part of this study. As a results, fibre optic is a good approach for instrumentations and monitoring for geotechnical structures as fibre optics is sensitive to the movement of the soil and fibre optic with anchorage system gave better strain measurement reading compare to without anchorage system.
5
Williams, William F. "Design and Full-Scale Testing of M50/P1 Bolt-Down Removeable Bollard System." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 41 (December 2018): 24–33. http://dx.doi.org/10.1177/0361198118798738.
Анотація:
The purpose of this project was to design and test a new bolt-down bollard system that meets the requirements of American Standards for Testing Materials (ASTM) Designation F2656-15 M50/P1 impact conditions. The test installation consisted of three vertical 10-in. diameter (nominal) bollards with welded base plates bolted to a shallow reinforced concrete foundation. The foundation for this system was sized to reduce the foundation embedment. Shallow foundations are often necessary for use in cities and urban areas where utilities can conflict with deeper foundations. Standard common members and materials were used in the installation to accommodate fabrication and installation in locations all over the world. The bollards can be removed to provide access if necessary. Full-scale testing was performed on the bolt-down bollard system. The bollard system design for this project successfully met the requirements of M50/P1 with a total payload penetration of less than 1 m. The new bollard design successfully met all the performance requirements for ASTM F2656-15 M50/P1. Details of the design and testing of the bolt-down bollard system are provided in this paper. Crash-testing videos and additional information on the design and full-scale testing will be provided in the presentation.
6
Davidovic, Nebojsa, Zoran Bonic, Verka Prolovic, Biljana Mladenovic, and Dragoslav Stojic. "A comparative theoretical-experimental analysis of settlements of shallow foundations on granular soil." Facta universitatis - series: Architecture and Civil Engineering 8, no. 2 (2010): 135–43. http://dx.doi.org/10.2298/fuace1002135d.
Анотація:
The paper presents a brief description of experiment within the research project 'Theoretical and experimental analysis of interaction of shallow reinforced concrete foundations and soil for the purpose of improvement of national regulations and implementaation of Eurocode system' where in situ tests of a series of reinforced concrete foundation footing were performed, by loading until failure. As a rule, methods for calculation of shallow foundations settlement on granular soils overestimate the expected settlement, and underestimate soil bearing capacity, which results in a conservative foundation design. In order to test accuracy and reliability of the different settlements prediction methods, a comparative analysis of settlements calculated using these methods and those measured during experiment, was performed.
7
Kutter, Bruce L., Mark Moore, Manouchehr Hakhamaneshi, and Casey Champion. "Rationale for Shallow Foundation Rocking Provisions in ASCE 41-13." Earthquake Spectra 32, no. 2 (May 2016): 1097–119. http://dx.doi.org/10.1193/121914eqs215m.
Анотація:
ASCE 41-13 supports three methods of modeling the soil-structure interaction for rocking footings as components of a foundation-building system: Method 1 uses uncoupled moment, shear, and axial springs; Method 2 uses a nonlinear gapping bed of springs; and Method 3 is used for structural footings that are flexible relative to the underlying soil. New component action tables in ASCE 41-13 provide modeling parameters and acceptance criteria for nonlinear and linear analysis of shallow foundation components. The values in the component action tables for nonlinear procedures were largely based upon analysis of foundation performance in model tests on rocking foundations. The primary measure to assess foundation performance is residual settlement or uplift. The acceptance criteria for linear analysis procedures ( m-factors) were derived from the allowable rotations for nonlinear procedures. A design example is presented in an online Appendix to illustrate differences between the current and previous versions of ASCE 41 and ASCE 31.
8
Kim, Dong-Kwan, Hong-Gun Park, Dong-Soo Kim, and Hyerin Lee. "Nonlinear system identification on shallow foundation using Extended Kalman Filter." Soil Dynamics and Earthquake Engineering 128 (January 2020): 105857. http://dx.doi.org/10.1016/j.soildyn.2019.105857.
9
Kovar, James, Nauman Sheikh, Roger Bligh, Sofokli Cakalli, Taya Retterer, and Jon Ries. "Development and Testing of Structurally Independent Foundations for High-Speed Containment Concrete Barrier." Transportation Research Record: Journal of the Transportation Research Board 2675, no. 4 (January 11, 2021): 297–307. http://dx.doi.org/10.1177/0361198120980325.
Анотація:
This paper presents the development and testing of single slope barriers with independent foundations that can be installed at a wide range of site conditions. The researchers developed designs of barriers with foundation systems by conducting a series of finite element simulations and performing full-scale vehicle impact tests under the American Association of State Highway and Transportation Officials’ (AASHTO) Manual for Assessing Safety Hardware ( MASH) Test Level 5 (TL-5) and Test Level 4 (TL-4) conditions. In this process, foundation designs were developed for site conditions that may require shallow foundations, or foundations that have a smaller footprint. Depending on the site conditions and the presence of underground structures, designers could select the most fitting option from these designs. Impact performance of the developed barrier and foundation systems was evaluated using full-scale finite element impact simulations under MASH TL-5 and TL-4 impact conditions. Two critical systems were selected for full-scale crash testing: a 54 in. tall single slope barrier with drilled shaft foundations, and a 36 in. tall single slope barrier with moment slab foundation. The barrier with the drilled shaft foundation system was tested to MASH Test 5-12 conditions, and the barrier with the moment slab foundation system was tested to MASH Test 4-12 conditions. Both systems performed acceptably with respect to the MASH criteria. This paper presents the various barrier and foundation designs that were developed, key results from the simulation analyses, and details of the crash testing performed on the two selected systems.
10
Itoh, K., X. Zeng, M. Koda, O. Murata, and O. Kusakabe. "Centrifuge Simulation of Wave Propagation due to Vertical Vibration on Shallow Foundations and Vibration Attenuation Countermeasures." Journal of Vibration and Control 11, no. 6 (June 2005): 781–800. http://dx.doi.org/10.1177/1077546305054150.
Анотація:
When constructing a high-speed railway system in an urban area, the reduction of the ground vibration and noise generated by train passages is a vitally important environmental consideration. In this paper we focus on the development of a centrifuge vibration testing system, which can simulate dynamic loading acting on shallow foundations. The system is used to generate vertical vibration similar to that generated by high-speed trains. The characteristics of wave propagation in a shallow circular foundation on sand are investigated. The effects of two types of barriers on vibration reduction are studied. Additionally, the impact of using vibration attenuating materials to build trackbeds is evaluated.
11
Kumar, Ravinesh, Supriya Mohanty, and Chethan K. "3D Seismic Response Analysis of Shallow Foundation Resting on Sandy Soil." International Journal of Geotechnical Earthquake Engineering 10, no. 1 (January 2019): 61–76. http://dx.doi.org/10.4018/ijgee.2019010105.
Анотація:
In the present study, an attempt has been made to study the response of a shallow foundation resting on medium dense sandy soil under seismic excitation. Numerical analysis of the soil-foundation system has been carried out using 3D finite element software OpenSeesPL. The effect of boundary conditions (shear beam and rigid box type) and the water table (0 m, 1 m and 2 m below the ground surface) on the response of soil-foundation system under seismic excitation have been analysed. The responses of the soil-foundation system are presented in the form of acceleration, displacement, excess pore pressure, excess pore pressure ratio and settlement variations at different locations in the soil domain. The results of the numerical analysis indicate that the peak acceleration, displacement, excess pore pressure and settlement values are found to be more in shear beam type boundary condition than that of a rigid box type boundary condition. Hence, rigid confinement and lower water table can reduce the liquefaction potential of the soil-foundation system under seismic excitation.
12
Ahmed, Danish, Siti Noor Linda Bt Taib, Tahar Ayadat, and Alsidqi Hasan. "Numerical Analysis of the Carrying Capacity of a Piled Raft Foundation in Soft Clayey Soils." Civil Engineering Journal 8, no. 4 (April 1, 2022): 622–36. http://dx.doi.org/10.28991/cej-2022-08-04-01.
Анотація:
Piled raft foundations are a common type of foundation for high-rise buildings. Unlike shallow foundations, deep foundations (piles) pass through weak or soft soil deposits and can reach stiff soil or bedrock to support the weight of the structure. In this paper, the performance of a medium embedment depth piled raft foundation in soft soil is presented. A numerical model was developed and a parametric study was conducted in order to simulate the case of such a foundation system and to investigate its performance in soft clay. This parametric study investigated the effect of the geometry of a piled raft foundation and the stiffness ratio between the pile material and clay on the performance of the foundation system in soft soil. Additionally, the failure mechanism of such a foundation system under load was examined. An analytical model was developed to predict the ultimate carrying capacity based on the observed failure mechanism. A semi-empirical model is proposed for determining the Improvement Factor (IF) of a given soil, pile, and geometric condition. Findings of the study indicate that the performance of piled raft foundations on soft soils is significantly affected by the piles’ spacing. As the ratio S/D increases, the ultimate carrying capacity of a piled raft foundation decreases. However, when this ratio exceeds 10 (S/D> 10), piles have little or no effect on the ultimate carrying capacity of this foundation system. A piled raft foundation system fails by bearing at the base of the piles and also by shear at the side of the pile group on hyperbolic plans. Doi: 10.28991/CEJ-2022-08-04-01 Full Text: PDF
13
Hokmabadi, Aslan S., and Behzad Fatahi. "Influence of Foundation Type on Seismic Performance of Buildings Considering Soil–Structure Interaction." International Journal of Structural Stability and Dynamics 16, no. 08 (August 25, 2016): 1550043. http://dx.doi.org/10.1142/s0219455415500431.
Анотація:
In selecting the type of foundation best suited for mid-rise buildings in high risk seismic zones, design engineers may consider that a shallow foundation, a pile foundation, or a pile-raft foundation can best carry the static and dynamic loads. However, different types of foundations behave differently during earthquakes, depending on the soil–structure interaction (SSI) where the properties of the in situ soil and type of foundation change the dynamic characteristics (natural frequency and damping) of the soil–foundation–structure system. In order to investigate the different characteristics of SSI and its influence on the seismic response of building frames, a 3D numerical model of a 15-storey full-scale (prototype) structure was simulated with four different types of foundations: (i) A fixed-based structure that excludes the SSI, (ii) a structure supported by a shallow foundation, (iii) a structure supported by a pile-raft foundation in soft soil and (iv) a structure supported by a floating (frictional) pile foundation in soft soil. Finite difference analyzes with FLAC3D were then conducted using real earthquake records that incorporated material (soil and superstructure) and geometric (uplifting, gapping and [Formula: see text] effects) nonlinearities. The 3D numerical modeling procedure had previously been verified against experimental shaking table tests conducted by the authors. The results are then presented and compared in terms of soil amplification, shear force distribution and rocking of the superstructure, including its lateral deformation and drift. The results showed that the type of foundation is a major contributor to the seismic response of buildings with SSI and should therefore be given careful consideration in order to ensure a safe and cost effective design.
14
Tan, Mengxi, and Sai K. Vanapalli. "Performance estimation of a shallow foundation on an unsaturated expansive soil slope subjected to rainfall infiltration." MATEC Web of Conferences 337 (2021): 03009. http://dx.doi.org/10.1051/matecconf/202133703009.
Анотація:
In the last two decades, there has been a significant increase in infrastructure development on slopes of hilly regions of the world, due to population growth. There are many infrastructures on unsaturated expansive slopes, especially in semi-arid and arid regions. Rainfall infiltration is one of the major factors that contributes to the slope and infrastructure foundations failures on hilly slopes with unsaturated expansive soils. In the current study, a rational approach is proposed considering the combined influence of the foundation-slope behavior based on the principles of unsaturated soil mechanics. This is achieved by a novel numerical modelling approach using the commercial software Geo-studio to investigate the performance of strip foundation located on the top of the unsaturated expansive soil slope subjected to various rainfall infiltration conditions. Hydro-mechanical coupling analysis is conducted to evaluate the rainfall water infiltration influence combined with slope stability analysis using limit equilibrium method. Comparisons are made between both the foundation bearing capacity, slope stability before and after rainfall water infiltration. Different failure mechanisms of the foundation and slope system are presented with and without foundation loading for various rainfall scenarios. Results summarized in this paper are helpful for the geotechnical engineers for understanding the performance of shallow foundations on unsaturated expansive soil slopes considering the influence of rainfall infiltration conditions.
15
Hakhamaneshi, Manouchehr, Bruce L. Kutter, Andreas G. Gavras, Sivapalan Gajan, Angelos Tsatsis, Weian Liu, Keshab Sharma, et al. "Database of rocking shallow foundation performance: Slow-cyclic and monotonic loading." Earthquake Spectra 36, no. 3 (March 16, 2020): 1585–606. http://dx.doi.org/10.1177/8755293020906564.
Анотація:
Many physical model tests have examined the performance of rocking foundations during cyclic and seismic loading. These tests varied in model size, testing equipment, superstructure properties, footing shape, supporting soil environment, and loading protocol. “FoRCy, Foundation Rocking database of Cyclic and Monotonic Loading” is a new database (published at https://datacenterhub.org/ ), summarizing the results of monotonic and slow-cyclic loading tests of rocking foundations. The database consists of columns identifying testing equipment and facility, soil, superstructure, and system properties, as well as loading protocol and results. The database contains 456 records (rows), each one being unique in either model configuration or loading amplitude. To illustrate its value, this article shows correlations between (1) settlement, rotation, and factor of safety with respect to bearing capacity and (2) moment and cumulative rotation for shallow footings. Data indicate that the rotation required to mobilize the moment capacity is surprisingly constant (about 0.01 radians) for a wide range of experiments.
16
Thomé, Antônio, Maciel Donato, Nilo Cesar Consoli, and James Graham. "Circular footings on a cemented layer above weak foundation soil." Canadian Geotechnical Journal 42, no. 6 (December 1, 2005): 1569–84. http://dx.doi.org/10.1139/t05-069.
Анотація:
This work proposes a method for predicting the behavior of shallow footings bearing on an upper layer of processed cemented soil that overlies a lower layer of weakly bonded residual soil with a high void ratio. The paper describes the results of a series of field plate tests and numerical simulations. The results lead to a semi-empirical method for designing shallow foundations on a double-layer system. The method has been validated by comparison of predicted values with results from a separate series of plate-loading tests. For engineering practice, the proposed method provides acceptable predictions of bearing capacities and loadsettlement curves.Key words: footings, cemented layer, layered system, weakly bonded, high void ratio.
17
Jiao, Shen Hua, Jin An Wang, and Ya Ming Liu. "Exploration and Practice of Innovative Support System of Large-Scale Deep Foundation Pit in Beijing." Advanced Materials Research 838-841 (November 2013): 747–55. http://dx.doi.org/10.4028/www.scientific.net/amr.838-841.747.
Анотація:
Foundation pit engineering is a critical part during the development process of underground space. With the increasing demands of underground space, foundation pit engineering is exposed to new challenges. This article firstly reviews the main features of shallow foundation pits in Beijing as well as the relevant design concepts of support, and then elaborates the features and challenges of urban large-scale deep foundation pits; a case study was introduced with the exploring practice of design and construction of the large-scale deep foundation pit of Wangjing SOHO project, the innovations of support design for this foundation pit are summarized; new prospects for development of support techniques of foundation pits are proposed.
18
Soares, Wilson Cartaxo, Roberto Quental Coutinho, and Renato Pinto da Cunha. "Piled raft with hollow auger piles founded in a Brazilian granular deposit." Canadian Geotechnical Journal 52, no. 8 (August 2015): 1005–22. http://dx.doi.org/10.1139/cgj-2014-0087.
Анотація:
Geotechnical projects typically achieve load transfer to the ground using shallow or deep foundations. The conventional design approach does not provide for the combination of these two types of foundation. The piled raft philosophy allows the association of the soil elements, raft, and piles to obtain technical and economic advantages over conventional design. The city of João Pessoa, in northeastern Brazil, has developed foundation practices with hollow auger piles in piled raft design. The coastal area of the city has topsoil layers with favorable conditions for using such a technique. This paper addresses the results of a research project with instrumented load tests on foundation systems of hollow auger piles and a piled raft. The analysis is based on the load–settlement curve through extrapolation criteria. The Poulos–Davis–Randolph (PDR) method is applied according to a trilinear and hyperbolic approach to simulate the load–settlement curve of piled rafts. The results indicate that the raft absorbs most of the load, and the raft–soil contact significantly increases the load capacity of the foundation. The PDR hyperbolic method could apply to practical use in the foundations of the region, as it allows a more detailed assessment of the behavior of the foundation and can forecast the behavior of the (locally nontraditional) piled raft foundation system.
19
Paolucci, Roberto, Raffaele Figini, and Lorenza Petrini. "Introducing Dynamic Nonlinear Soil-Foundation-Structure Interaction Effects in Displacement-Based Seismic Design." Earthquake Spectra 29, no. 2 (May 2013): 475–96. http://dx.doi.org/10.1193/1.4000135.
Анотація:
An iterative linear-equivalent procedure to take into account nonlinear soil-structure interaction effects in the displacement-based seismic design is presented for the case of shallow foundations. The procedure is based on the use of empirical curves to evaluate the stiffness degradation and the increase of damping ratio as a function of foundation rotation. Iterations are performed to ensure that admissible values of foundation rotations are complied with, in addition to the standard checks on structural displacements and drifts. Some examples of application of the approach to the design of bridge piers are provided. Design results are checked by means of nonlinear dynamic time-history analyses performed by a macro-element-based numerical tool, assuming nonlinear behavior of both structure and soil-foundation system.
20
Cheng, Zhihe, and Yousheng Deng. "Bearing Characteristics of Moso Bamboo Micropile-Composite Soil Nailing System in Soft Soil Areas." Advances in Materials Science and Engineering 2020 (August 12, 2020): 1–17. http://dx.doi.org/10.1155/2020/3204285.
Анотація:
Based on the characteristics of moso bamboo including high short-term strength, stable performance, and ability to provide temporary support for shallow foundation pits in soft soil, the stress characteristics and supporting effects of the ecological composite supporting system have been explored through model tests and numerical calculation analysis of the moso bamboo micropile-composite soil nailing structure. The results showed that the bamboo pile can effectively control the horizontal deformation of the side wall of the foundation pit and the ground surface settlement, achieving a relatively satisfactory supporting effect. Furthermore, the bamboo pile has visibly bent in middle and lower parts, where the regional shear point is most likely to appear, the axial force of the soil nail is distributed in an oval pattern with a smaller force on both sides and a larger force in the middle part, the maximum axial strain is 447.3 με, and the axial force of the soil nails in each row follows a similar trend. The synergy of piles and soil nails can delay the formation of the slip surface, therefore enhancing the overall bearing capacity of the foundation pit. These results can shed light on the support mechanism and engineering design of bamboo piles in shallow soft soil foundation pits.
21
Mohammed, Mariamme, Ahmad Sharafati, Nadhir Al-Ansari, and Zaher Mundher Yaseen. "Shallow Foundation Settlement Quantification: Application of Hybridized Adaptive Neuro-Fuzzy Inference System Model." Advances in Civil Engineering 2020 (February 22, 2020): 1–14. http://dx.doi.org/10.1155/2020/7381617.
Анотація:
Settlement simulating in cohesion materials is a crucial issue due to complexity of cohesion soil texture. This research emphasis on the implementation of newly developed machine learning models called hybridized Adaptive Neuro-Fuzzy Inference System (ANFIS) with Particle Swarm Optimization (PSO) algorithm, Ant Colony optimizer (ACO), Differential Evolution (DE), and Genetic Algorithm (GA) as efficient approaches to predict settlement of shallow foundation over cohesion soil properties. The width of footing (B), pressure of footing (qa), geometry of footing (L/B), count of SPT blow (N), and ratio of footing embedment (Df/B) are considered as predictive variables. Nonhomogeneity and inconsistency of employed dataset is a major concern during prediction modeling. Hence, two different modeling scenarios (i) preprocessed dataset (PP) and (ii) nonprocessed (initial) dataset (NP) were inspected. To assess the accuracy of the applied hybrid models and standalone one, multiple statistical metrics were computed and analyzed over the training and testing phases. Results indicated ANFIS-PSO model exhibited an accurate and reliable prediction data intelligent and had the highest predictability performance against all employed models. In addition, results demonstrated that data preprocessing is highly essential to be performed prior to building the predictive models. Overall, ANFIS-PSO model showed a robust machine learning for settlement prediction.
22
Li, Wei, Fei Gao, He Huang, Haruyuki Yamamoto, and Kinji Takeuchi. "Consolidation Settlement Analyses on a Composite Foundation System Combined with Walled and Columniform Soil Improvement." Advanced Materials Research 163-167 (December 2010): 2318–27. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2318.
Анотація:
To satisfy the geotechnical strength requirements and the serviceability requirements, types of foundation systems (such as shallow foundation, pile foundation and composite foundation) have been developed. Of course, the type of foundation system is determined by many factors such as ground condition, economy and environmental influence of construction. To cope with weak or compressible soils, the authors present a raft foundation system with walled and columniform soil improvement for multistory buildings, which is economical and environment-friendly. In this raft foundation system, different columniform soil improvements in size and depth are used, and the subgrade under the edge of the foundation is walled by soil improvement. It can effectively control differential settlement and prevent relative rising of the structure by adjusting the size and depth of columniform soil improvements according to the soil layer difference of geological situation under the building. We have performed series numerical analyses under two-dimensional plane strain condition to study the settlement behaviors of the composite foundation system, and its effects on controlling differential settlement and improving bearing capacity were verified for immediate condition. As a continuous research, consolidation settlement analyses are performed, the process of excess hydraulic pressure dispersion with time and the consolidation settlement development are studied in this paper.
23
Trofymchuk, Oleksandr, and Oleh Savytskyi. "Vertical Impedance of Rigid Shallow Foundation on Layered Water-Saturated Soil." Modeling, Control and Information Technologies, no. 3 (November 6, 2019): 165–67. http://dx.doi.org/10.31713/mcit.2019.48.
Анотація:
Methods have been developed for numerical analysis the vertical oscillations of rigid plate with a liquidimpermeable sole rested on the layer (Biot’s model) with a rigidly restrained lower edge. The plate sole is liquid-impermeable. The analysis of the impedance functions depending on the oscillation frequency, the geometry of the system and the mechanical parameters of the soil model is carried out.
24
Taylor, Adam G., and Jae H. Chung. "Explanation and Application of the Evolving Contact Traction Fields in Shallow Foundation Systems." Geotechnics 2, no. 1 (January 14, 2022): 91–113. http://dx.doi.org/10.3390/geotechnics2010004.
Анотація:
The present paper provides a qualitative discussion of the evolution of contact traction fields beneath rigid shallow foundations resting on granular materials. A phenomenological similarity is recognized in the measured contact traction fields of rigid footings and at the bases of sandpiles. This observation leads to the hypothesis that the stress distributions are brought about by the same physical phenomena, namely the development of arching effects through force chains and mobilized intergranular friction. A set of semi-empirical equations are suggested for the normal and tangential components of this contact traction based on past experimental measurements and phenomenological assumptions of frictional behaviors at the foundation system scale. These equations are then applied to the prescribed boundary conditions for the analysis of the settlement, resistance, and stress fields in supporting granular materials beneath the footing. A parametric sensitivity study is performed on the proposed modelling method, highlighting solutions to the boundary-value problems in an isotropic, homogeneous elastic half-space.
25
Huynh, Van Quan, Xuan Huy Nguyen, and Trung Kien Nguyen. "A Macro-element for Modeling the Non-linear Interaction of Soil-shallow Foundation under Seismic Loading." Civil Engineering Journal 6, no. 4 (April 1, 2020): 714–23. http://dx.doi.org/10.28991/cej-2020-03091503.
Анотація:
This paper presents a macro-element for simulating the seismic behavior of the soil- shallow foundation interaction. The overall behavior in the soil and at the interface is replaced by a macro-element located at the base of the superstructure. The element reproduces the irreversible elastoplastic soil behavior (material non-linearity) and the foundation uplift (geometric non-linearity) at the soil- foundation interface. This new macro-element model with three degrees-of-freedom describes the force-displacement behavior of the footing center. The single element is restrained by the system of equivalent springs and dashpots. The footing is considered as a rigid body. It is solved by a suitable Newmark time integration scheme and implemented in Matlab to simulate the nonlinear behavior of soil-shallow foundation interaction under seismic loading. A reduce scaled soil-foundation system has been tested on a shaking table at the University of Transport and Communications, Hanoi, Vietnam. Five series of earthquake motions were used with maximum acceleration increased from 0.5 to 2.5 . The comparison of numerical results obtained from the simulation and experimentations shows the satisfactory agreement of the model. The proposed macro-element can be used to predict the seismic behavior of a wider variety of configurations.
26
Reddy, M. V. Ravi Kishore, Supriya Mohanty, and Rehana Shaik. "Seismic Performance of Soil-Ash and Soil-Ash-Foundation System." International Journal of Geotechnical Earthquake Engineering 11, no. 1 (January 2020): 45–70. http://dx.doi.org/10.4018/ijgee.2020010103.
Анотація:
In this study, a 3D seismic response of soil deposit, soil-ash deposit and soil-ash-foundation system was investigated. Homogeneous sand deposit of 80m × 9m × 20m was initially analyzed. A pond ash layer is on top of the sand deposit with varying thicknesses and the efficiency of the pond ash layer on the sand deposit was evaluated for its best suitability. The optimum sand-ash deposit overlain by a shallow foundation has been analysed under the excitation of the Nepal (Mw:7.8) and North East India earthquake (Mw:7.5). A seismic response analysis was performed using finite element software PLAXIS3D. The finite element model adopted for the present study has been validated using 1D nonlinear ground response analysis programs. e.g. DEEPSOIL and Cyclic1D. Results of the response analysis have been determined in terms of acceleration, displacement, excess pore pressure, and excess pore pressure ratio. It was observed that, the sand-pond ash-foundation system experienced liquefaction when excited under the Nepal earthquake motion whereas it is safe against the North East India earthquake.
27
Pender, M. J. "Earthquake resistant design of foundations." Bulletin of the New Zealand Society for Earthquake Engineering 29, no. 3 (September 30, 1996): 155–71. http://dx.doi.org/10.5459/bnzsee.29.3.155-171.
Анотація:
This paper reviews the main issues to be addressed in the design of shallow and deep foundations which may be subject to earthquake loading. Information is presented on the soil properties required as well as the various design analysis techniques with a view to assessing the current state-of-the-art and highlighting areas in which further techniques need to be developed. The paper sets out, by way of an overview, a sequence of steps that a designer may follow in developing a foundation system. It is concluded that, at present, the greatest deficiencies lie in the areas of most potential use to designers. A secondary aim of the paper is to enhance communication between geotechnical and structural engineers on aseismic foundation design.
28
Petridis, Christos, and Dimitris Pitilakis. "Fragility curve modifiers for reinforced concrete dual buildings, including nonlinear site effects and soil–structure interaction." Earthquake Spectra 36, no. 4 (June 22, 2020): 1930–51. http://dx.doi.org/10.1177/8755293020919430.
Анотація:
We investigate the influence of soil–structure interaction (SSI) and nonlinear soil behavior on the seismic fragility of reinforced concrete (RC) dual (frame + shear wall) buildings resting on shallow foundations. This article includes a holistic methodology to account for nonlinear soil behavior and soil–foundation–structure interaction in a modular way. Using nonlinear dynamic analyses, we derive fragility curves for a wide set of building typologies and soil profiles, showing that soil behavior during strong shaking significantly affects the vulnerability of the soil–foundation–structure system. The influence of SSI is pronounced mostly for soft soil profiles, varying in a building-specific way. Post-processing of our results evolves into a set of fragility modifiers that enable risk analysts to massively account for soil-related and/or SSI effects in large-scale risk assessments.
29
Farooq, Qazi U., and Muhammad T. Naqash. "Performance of Shallow Building Foundations under Infrequent Rainfall Patterns at Al-Madinah, Saudi Arabia." Open Civil Engineering Journal 15, no. 1 (April 22, 2021): 91–103. http://dx.doi.org/10.2174/1874149502115010091.
Анотація:
Objective: This research mainly emphasizes the sustainability of midrise buildings in the holy city of Al-Madinah under varying rainfall patterns. Background: Western Saudi Arabia is usually a dry region, and most of the buildings are designed considering unsaturated soil conditions. However, high-intensity unexpected rainfall events have been observed in recent times. This scenario alters the soil moisture conditions and exhibits a risk to the structural stability. Methods: In this study, Madinah Al-Munawara soil conditions are considered to analyse the isolated shallow foundation system. Finite element models are generated for dry and wet soil conditions by using the COMSOL Multiphysics program. The numerical analysis results indicate the possibility of higher settlements under saturated conditions. Simple 1-D experimental element model tests have also been conducted to analyze the effects of the moisture change on the pre-loaded shallow foundations. Results: The experimental results are qualitatively compared with numerical models to observe soil moisture's overall effects on the substructure. The research will contribute to the safety of existing structures and recommend parameters for future design projects. Conclusion: Shallow foundations on loose granular soils are vulnerable to moisture variations, and geotechnical conditions are critical to incorporate in the prospective design projects considering the changing climatic conditions.
30
Schwarz, Hans, Nikola Jocic, and David Bertermann. "Development of a Calculation Concept for Mapping Specific Heat Extraction for Very Shallow Geothermal Systems." Sustainability 14, no. 7 (April 1, 2022): 4199. http://dx.doi.org/10.3390/su14074199.
Анотація:
Horizontal shallow geothermal applications are easy to install, and their installation process is less liable to legislation than other geothermal systems. Due to a lack of planning guidance, the opportunity to implement such systems is often overlooked, although geothermal installations are urgently needed as a sustainable energy source. To give a foundation for including very shallow geothermal systems in local heat supply planning, potential maps are crucial. To enable their utilization in energy use plans or similar elaborations for municipalities, location-specific and system-specific heat extractions are required. Since applicable standards are not available, it is nearly impossible to provide aggregate propositions, which are essential for potential maps. In this study, a concept was evolved for deriving very shallow geothermal potential maps with location-specific and system-specific heat extraction values. As a basis, VDI 4640 Part 2 information regarding heat extraction and respective climate zone references was utilized. Furthermore, climate information and a soil map were needed to apply the concept to the study area. The application of the concept in an Austrian study area resulted in appropriate potential maps. Moreover, this concept is similarly applicable in other areas of interest.
31
Harden, Chad, Tara Hutchinson, and Mark Moore. "Investigation into the Effects of Foundation Uplift on Simplified Seismic Design Procedures." Earthquake Spectra 22, no. 3 (August 2006): 663–92. http://dx.doi.org/10.1193/1.2217757.
Анотація:
Uplifting of and yielding below shallow foundations supporting rigid lateral force–resisting elements can provide additional nonlinearity into a system's overall force-deformation behavior. While this nonlinearity may be advantageous, potentially reducing seismic demands, displacement compatibility may result in overstress of lateral and/or gravity-resisting elements. Incorporating this balance of benefit versus consequence in structural design is one goal of performance-based earthquake engineering (PBEE). There are a variety of approaches in design codes for estimating seismic demands and incorporating “performance” as a design goal. Such methods generally account for the displacement of an equivalent SDOF system by reducing the design strength, however, not explicitly for the case of foundation uplift. To address this shortcoming, this paper investigates the relationship between the strength ratio R and the displacement ratio C1 using the beam on nonlinear Winkler foundation (BNWF) concept. Numerical models were constructed considering a range of soil-structure natural periods and a range of design R values. Nineteen ground motions with a broad range of characteristics are used to conduct nonlinear time-history analyses. Results from these simulations indicate that current suggestions for C1- R relations are highly unconservative when uplifting foundations are anticipated. Revised C1- R relations for uplifting foundations are presented and an example numerical comparison provided.
32
Hamad Sfoog, Ehab, Alvin John Lim Meng Siang, Wael M. Albadri, Nahla Naji, Sim Sy Yi, and Nickholas Anting Anak Guntor. "Finite Element Modeling of Innovative Shallow Raft Foundation with Granular Pile Anchor System for Expansive Clays." IOP Conference Series: Materials Science and Engineering 713 (January 3, 2020): 012050. http://dx.doi.org/10.1088/1757-899x/713/1/012050.
33
Kolay, P. K., S. Kumar, and D. Tiwari. "Improvement of Bearing Capacity of Shallow Foundation on Geogrid Reinforced Silty Clay and Sand." Journal of Construction Engineering 2013 (June 19, 2013): 1–10. http://dx.doi.org/10.1155/2013/293809.
Анотація:
The present study investigates the improvement in the bearing capacity of silty clay soil with thin sand layer on top and placing geogrids at different depths. Model tests were performed for a rectangular footing resting on top of the soil to establish the load versus settlement curves of unreinforced and reinforced soil system. The test results focus on the improvement in bearing capacity of silty clay and sand on unreinforced and reinforced soil system in non-dimensional form, that is, BCR. The results show that bearing capacity increases significantly with the increased number of geogrid layers. The bearing capacity for the soil increases with an average of 16.67% using one geogrid layer at interface of soils with equal to 0.667 and the bearing capacity increases with an average of 33.33% while using one geogrid in middle of sand layer with equal to 0.33. The improvement in bearing capacity for sand underlain silty clay maintaining and equal to 0.33; for two, three and four number geogrid layer were 44.44%, 61.11%, 72.22%, respectively. The finding of this research work may be useful to improve the bearing capacity of soil for shallow foundation and pavement design for similar type of soil available elsewhere.
34
Hao, Dong Xue, Yu Cong Gao, and Rong Chen. "Estimation of Uplift Capacity of Excavated Foundation of Transmission Lines." Applied Mechanics and Materials 680 (October 2014): 361–64. http://dx.doi.org/10.4028/www.scientific.net/amm.680.361.
Анотація:
Finite element model for the system of foundation and its surrounding homogeneous soil is established based on software ABAQUS to analyze the uplift behavior of excavated foundation of transmission lines. The influence of soil properties and embedment ratio were analyzed. Deep mode occurs when embedment ratio is more than 4. As for shallow mode, the shearing method based on cylinder sliding surface was used to estimate uplift capacity. The expression of nominal uplift coefficient of earth pressure Ku in the formula was determined via back-calculation and fitting, which is the function of embedment ratio, friction angle and cohesion simultaneously. The errors of uplift capacity from fitting formula and numerical analysis are all within 15%.
35
Singh, Chamjeet, Jagdeep Singh, Sandeep Singh, and Vikas Kumar. "Performance of Inclined Skirt Footing: Numerical Analysis." IOP Conference Series: Earth and Environmental Science 889, no. 1 (November 1, 2021): 012076. http://dx.doi.org/10.1088/1755-1315/889/1/012076.
Анотація:
Abstract The skirt footings are considered as alternate to enhance the bearing capacity of shallow foundation on sandy soil as an alternate of deep foundation. The experimental data of paper titled “Performance of skirt strip footing subjected to eccentric inclined load was consider as base for validation and other parameters of material for numerical investigation for different conditions. Numerical analysis was conducted to determine the behavior of two-sided skirt footing on eccentric loading with different angle and projections provided to skirt. The study reveals good impact of skirt angle and skirt projection lengths on load capacity of footing system
36
Tran, H. H. T., K. C. Toh, and K. K. Phoon. "Preconditioned IDR(s) iterative solver for non-symmetric linear system associated with FEM analysis of shallow foundation." International Journal for Numerical and Analytical Methods in Geomechanics 37, no. 17 (February 4, 2013): 2972–86. http://dx.doi.org/10.1002/nag.2171.
37
Sirat, Qurratu Aini, Dayangku Salma Awang Ismail, Izwan Shah Ahmad, and Azman Kassim. "Strain monitoring for shallow foundation using the application of Brillouin Optical Time Domain Analysis sensing system (BOTDA)." IOP Conference Series: Materials Science and Engineering 932 (December 18, 2020): 012052. http://dx.doi.org/10.1088/1757-899x/932/1/012052.
38
Liu, Junwei, Zhipeng Wan, Xingke Dai, Dongsheng Jeng, and Yanping Zhao. "Experimental Study on Whole Wind Power Structure with Innovative Open-Ended Pile Foundation under Long-Term Horizontal Loading." Sensors 20, no. 18 (September 18, 2020): 5348. http://dx.doi.org/10.3390/s20185348.
Анотація:
The offshore wind energy (OWE) pile foundation is mainly a large diameter open-ended single pile in shallow water, which has to bear long-term horizontal cyclic loads such as wind and waves during OWE project lifetime. Under the complex cyclic loads, the stress and displacement fields of the pile-soil system change continuously, which affects the dynamic characteristics of the pile foundation. Within the service life of the pile foundation, the pile-soil system has irreversible cumulative deformation, which further causes damage to the whole structure. Therefore, it is important to examine the overall dynamic characteristics of wind power foundation under high cycle. In this paper, in the dry sand foundation, taking the Burbo Bank 3.6 MW offshore turbine-foundation structure as the prototype, the horizontal cyclic loading model tests of the wind power pile foundation with the scale of 1:50 were carried out. Considering the factors such as loading frequency and cyclic load ratio, the horizontal dynamic characteristics of the whole OWE pile foundation are studied. The comparison results between the maximum bending moment of pile and the fitting formula are discussed. In conclusion, moment of OWE pile shaft is corresponding to the loading frequency (f = 9 HZ) and loading cycles by fitting formulas. The fatigue damage of the OWE pile does not occurs with low frequencies in high cycles.
39
Ziccarelli, Maurizio, and Marco Rosone. "Influence of a Thin Horizontal Weak Layer on the Mechanical Behaviour of Shallow Foundations Resting on Sand." Geosciences 11, no. 9 (September 16, 2021): 392. http://dx.doi.org/10.3390/geosciences11090392.
Анотація:
The presence of minor details of the ground, including soil or rock masses, occurs more frequently than what is normally believed. Thin weak layers, shear bands, and slickensided surfaces can substantially affect the behaviour of foundations, as well as that of other geostructures. In fact, they can affect the failure mechanisms, the ultimate bearing capacity of footings, and the safety factor of the geotechnical system. In this research, numerically conducted through Finite Element Code Plaxis 2D, the influence of a horizontal thin weak layer on the mechanical behaviour of shallow footings was evaluated. The obtained results prove that the weak layer strongly influences both the failure mechanism and the ultimate bearing capacity if its depth is lower than two to four times the footing width. In fact, under these circumstances, the failure mechanisms are always mixtilinear in shape because the shear strains largely develop on the weak layer. However, the reduction in the ultimate bearing capacity is a function of the difference between the shear strength of the foundation soil and the layer. The presence of a thin weak layer decreases the ultimate bearing capacity up to 90%. In conclusion, this research suggests that particular attention must be paid during detailed ground investigations to find thin weak layers. Based on the obtained results, it is convenient to increase the soil volume investigation to a depth equal to four times the width of the foundation.
40
You, Shuang, Cheng-Han Zhang, and Peng Jiang. "Heat transfer performance and structure response of energy piles." Thermal Science 23, no. 3 Part A (2019): 1647–54. http://dx.doi.org/10.2298/tsci180602235y.
Анотація:
Energy pile becomes a new application of foundation, instead of the traditional ground source heat pump system. The heat exchange efficiency and its structural response induced by thermal stress is an urgent issue for the usage of shallow geothermal in foundations. In this study, the field experiments are systematically carried out by using engineering test pile as energy pile, the comprehensive thermal conductivity and heat exchange rate of each pile are achieved by thermal performance tests. Then the deformation and stress-strain of a heating or cooling pile at different temperature are analyzed to explore the influence of thermal stress on pile structure. Finally, the thermal stress distribution along the pile is calculated, and its bearing capability is analyzed. The results are applied to the design and application of energy piles.
41
Soelarso, E. Antaluca, J. L. Batoz, and F. Lamarque. "On the finite element bearing capacity analysis of a rib system to be used as shallow foundation construction." IOP Conference Series: Materials Science and Engineering 673 (December 10, 2019): 012030. http://dx.doi.org/10.1088/1757-899x/673/1/012030.
42
Bao, Xiaohua, Guanlin Ye, Bin Ye, Yanbin Fu, and Dong Su. "Co-seismic and post-seismic behavior of an existed shallow foundation and super structure system on a natural sand/silt layered ground." Engineering Computations 33, no. 1 (March 7, 2016): 288–304. http://dx.doi.org/10.1108/ec-05-2015-0134.
Анотація:
Purpose – The purpose of this paper is to evaluate the co-seismic and post-seismic behaviors of an existed soil-foundation system in an actual alternately layered sand/silt ground including pore water pressure, acceleration response, and displacement et al. during and after earthquake. Design/methodology/approach – The evaluation is performed by finite element method and the simulation is performed using an effective stress-based 2D/3D soil-water coupling program DBLEAVES. The calculation is carried out through static-dynamic-static three steps. The soil behavior is described by a new rotational kinematic hardening elasto-plastic cyclic mobility constitutive model, while the footing and foundation are modeled as elastic rigid elements. Findings – The shallow (short-pile type) foundation has a better capacity of resisting ground liquefaction but large differential settlement occurred. Moreover, most part of the differential settlement occurred during earthquake motion. Attention should be paid not only to the liquefaction behavior of the ground during the earthquake motion, but also the long-term settlement after earthquake should be given serious consideration. Originality/value – The co-seismic and post-seismic behavior of a complex ground which contains sand and silt layers, especially long-term settlement over a period of several weeks or even years after the earthquake, has been clarified sufficiently. In some critical condition, even if the seismic resistance is satisfied with the design code for building, detailed calculation may reveal the risk of under estimation of differential settlement that may give rise to serious problems.
43
Bienen, B., and M. J. Cassidy. "Three-dimensional numerical analysis of centrifuge experiments on a model jack-up drilling rig on sand." Canadian Geotechnical Journal 46, no. 2 (February 2009): 208–24. http://dx.doi.org/10.1139/t08-115.
Анотація:
Jack-up drilling rigs are usually founded on three shallow footings. Under wind, wave, and current loading offshore, the footings of these tall multi-footing systems transfer large moment loads in addition to self-weight, horizontal load, and even torsion to the underlying soil. To be able to deploy a jack-up safely at a particular offshore site, the unit’s capacity to withstand a 50 year return period storm is required to be checked in accordance with current guidelines (Site specific assessment of mobile jack-up units, The Society of Naval Architects & Marine Engineers). As the overall system behaviour is influenced significantly by the footing restraint, models that account for the complex nonlinear foundation–soil interaction behaviour are required to be integrated with the structural and loading models. Displacement-hardening plasticity theory has been suggested as an appropriate framework to formulate force-resultant models to predict shallow foundation behaviour. Recent research has extended such a model to account for six degree-of-freedom loading of circular footings on sand, allowing integrated structure–soil analysis in three dimensions. This paper discusses “class A” numerical predictions of experiments on a model jack-up in a geotechnical centrifuge, using the integrated modelling approach, and critically evaluates the predictive performance. The numerical simulations are shown to represent a significant improvement compared with the method outlined in the current guidelines.
44
Kozunova, Oksana, and Kristina Sirosh. "Nonlinear analysis of a crossing-beams system on an elastic with usage of the Mathematica software." MATEC Web of Conferences 350 (2021): 00005. http://dx.doi.org/10.1051/matecconf/202135000005.
Анотація:
In this paper, the authors consider the method of calculating an infinite system of cross beams on an elastic base by the variationaldifference method. The system of cross beams on an elastic base is most often modeled as shallow strip foundations for buildings of various functional purposes. The variation-difference method is one of the numerical and analytical methods for calculating building structures, it is based on the variational principles of the Ritz-Timoshenko method and on the minimum of the total potential energy of the entire system according to the Lagrange principle, and is also close to the real operating conditions of the foundation – base. A single-layer isotropic artificial base was used as an elastic base in the work, as an elastic layer limited in thickness. The algorithm of nonlinear calculation is based on the use of the iterative method of elastic solutions. The physical nonlinearity of the material of reinforced concrete beams is taken into account through the asymptotic dependence “Moment-curvature”. Numerical approbation of the results of elastic and nonlinear calculations of the system of cross beams on an elastic base was carried out using the MATHEMATICA software package.
45
Aresti, Lazaros, Paul Christodoulides, Gregoris P. Panayiotou, and Georgios Florides. "Residential Buildings’ Foundations as a Ground Heat Exchanger and Comparison among Different Types in a Moderate Climate Country." Energies 13, no. 23 (November 28, 2020): 6287. http://dx.doi.org/10.3390/en13236287.
Анотація:
Shallow Geothermal Energy Systems (SGESs) constitute Renewable Energy Systems (RES), which find application in the residential sector through the use of Ground Source Heat Pumps (GSHPs). GSHPs are associated with Ground Heat Exchangers (GHEs), whereby heat is gained/lost through a network of tubes into the ground. GSHPs have failed to flourish in the RES market due to their high initial costs and long payback periods. In this study, the use of Energy Geo-Structure (EGS) systems, namely, the foundation (or energy) piles and the foundation bed of a residential building in Cyprus, was computationally modeled in the COMSOL Multiphysics software. First, the single-houses’ trend in number of units and area in Cyprus was examined and a theoretically typical house with nearly Zero Energy Building (nZEB) characteristics was considered. The heating and cooling loads were estimated in the TRNSYS software environment and used as inputs to investigate the performance of the GSHP/GHE systems. Both systems were shown to exhibit steady performance and high Coefficient of Performance (COP) values, making them an alternative RES solution for residential building integration. Next, the systems were economically evaluated through a comparison with a convectional Air Source Heat Pump (ASHP) system. The economic analysis showed that the cost of the suggested conversions of the foundation elements into GHEs had short payback periods. Consequently, either using the foundation piles or bed as a GHE is a profitable investment and an alternative to conventional RES.
46
Emani, Pavan Kumar, Ritesh Kumar, and Phanikanth Vedula. "Inelastic Response Spectrum for Seismic Soil Pile Structure Interaction." International Journal of Geotechnical Earthquake Engineering 7, no. 2 (July 2016): 24–34. http://dx.doi.org/10.4018/ijgee.2016070102.
Анотація:
Structures resting on deep foundations like pile groups are subjected to entirely different kind of vibrations than those resting on shallow foundations, due to the inherent variations in the ground motions experienced at various levels of the foundation. The present work tries to generate response spectrum for single-pile supported structures using inelastic dynamic soil-pile interaction analysis. In the numerical model, the soil nonlinearity includes both separation at soil-pile interface and the plasticity of the near-field soil. The radiation boundary condition is also incorporated in the form of a series of far-field dampers which absorb the out-going waves. Inelastic response spectra for the structure, represented by a SDOF system, is generated after applying the synthetic time histories compatible with design (input) response spectra (as per IS 1893:2002-part I) at the base of pile to investigate the effects of ground response analysis including kinematics and inertial interaction between soil- pile system. It is found that a structure supported by pile foundations should be designed for larger seismic forces/ accelerations than those obtained from the design spectrum given in IS 1893:2002-Part I. The verification of the developed MATLAB program is reported towards the end, using results from commercial Finite Element software ABAQUS.
47
Taylor, Adam G., and Jae H. Chung. "Analysis of tangential contact boundary value problems using potential functions." Royal Society Open Science 6, no. 3 (March 2019): 182106. http://dx.doi.org/10.1098/rsos.182106.
Анотація:
This paper presents an analysis technique of high-order contact potential problems and its application to an elastic settlement analysis of a shallow foundation system subjected to a combined traction boundary condition. Closed-form solutions of potential functions are derived for an elastic half-space subjected to bilinear tangential traction boundary conditions over rectangular surface regions. Using the principle of superposition, the present solutions provide a means to form an approximate and continuous solution of elastic contact problems with higher-order tangential boundary conditions. As an application example, an elastic settlement analysis of a rigid footing founded on a dense granular soil is performed under a tangential traction boundary condition prescribed in an analogy with the stress equilibrium states of static sandpiles. A generalized solution approach to combined normal and tangential traction boundary value problems is discussed in the context of foundation engineering.
48
Albrecht, Bruce, Virendra Ghate, Johannes Mohrmann, Robert Wood, Paquita Zuidema, Christopher Bretherton, Christian Schwartz, et al. "Cloud System Evolution in the Trades (CSET): Following the Evolution of Boundary Layer Cloud Systems with the NSF–NCAR GV." Bulletin of the American Meteorological Society 100, no. 1 (January 2019): 93–121. http://dx.doi.org/10.1175/bams-d-17-0180.1.
Анотація:
AbstractThe Cloud System Evolution in the Trades (CSET) study was designed to describe and explain the evolution of the boundary layer aerosol, cloud, and thermodynamic structures along trajectories within the North Pacific trade winds. The study centered on seven round trips of the National Science Foundation–National Center for Atmospheric Research (NSF–NCAR) Gulfstream V (GV) between Sacramento, California, and Kona, Hawaii, between 7 July and 9 August 2015. The CSET observing strategy was to sample aerosol, cloud, and boundary layer properties upwind from the transition zone over the North Pacific and to resample these areas two days later. Global Forecast System forecast trajectories were used to plan the outbound flight to Hawaii with updated forecast trajectories setting the return flight plan two days later. Two key elements of the CSET observing system were the newly developed High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER) Cloud Radar (HCR) and the high-spectral-resolution lidar (HSRL). Together they provided unprecedented characterizations of aerosol, cloud, and precipitation structures that were combined with in situ measurements of aerosol, cloud, precipitation, and turbulence properties. The cloud systems sampled included solid stratocumulus infused with smoke from Canadian wildfires, mesoscale cloud–precipitation complexes, and patches of shallow cumuli in very clean environments. Ultraclean layers observed frequently near the top of the boundary layer were often associated with shallow, optically thin, layered veil clouds. The extensive aerosol, cloud, drizzle, and boundary layer sampling made over open areas of the northeast Pacific along 2-day trajectories during CSET will be an invaluable resource for modeling studies of boundary layer cloud system evolution and its governing physical processes.
49
Gutiérrez-Martín, Alfonso, José I. Yenes, Marta Fernández-Hernández, and Ricardo Castedo. "Stabilization Methodology in Foundation Soils by ERT-3D Application in Estepona, South Spain." Applied Sciences 11, no. 10 (May 13, 2021): 4455. http://dx.doi.org/10.3390/app11104455.
Анотація:
The paper proposes a novel methodology for the stabilization of shallow foundations, with a simplified model combined with 3D electrical resistivity tomography (ERT-3D and consolidation injections. To determine its usefulness, the method has been applied in a case located in Estepona (southern Spain). The chosen tomography model is the dipole–dipole configuration, with an optimized distance between electrodes of 0.80 m for a better visualization of the foundation subsoil; with this parameterization, a total of 72 electrodes were installed in the analyzed case. In this work, the depth of the anomaly in the building’s supporting subsoil was detected ranging from 2.00 m to 3.90 m deep. The study also delineates areas of high resistivity variations (50–1000 Ω m) in the middle and eastern end of the field. These data have been validated and corroborated with a field campaign. The results of the ERT-3D monitoring are presented, once the investment data has been processed with the RES3DINV software, from the beginning to the end of the stabilization intervention. The novelty occurs with the interaction between the tomography and the foundation consolidation injections, until the final stabilization. This is a very useful methodology in case of emergency consolidation, where there is a need to minimize damage to the building. Thus, people using this combined system will be able to practically solve the initial anomalies of the subsoil that caused the damages, in a non-invasive way, considerably lowering the value of the resistivities.
50
Wei, Gang, and Hao Qiang Yu. "Study on Effect of Frame Structures Crossed by Shallow-Buried and Mining Tunnelling." Advanced Materials Research 1065-1069 (December 2014): 341–46. http://dx.doi.org/10.4028/www.scientific.net/amr.1065-1069.341.
Анотація:
During the shallow-buried tunnel excavation, the formation will be affected and the nearby buildings will be caused fracture. By using three dimensional software MIDAS/GTS, the interactions among structures-soil-tunnel system is considered in this paper, and the working condition of shallow-buried underground excavation is simulated in the independent foundation of frame structures. It is indicated that building will tilt to the side of tunnel as the horizontal distance L between building and tunnels is increasing, after reaching certain distance, the influence to the building tends to little, at the same time, the maximum first principal stress P1 and maximum deformation rate E1 show a trend of decrease. When the kind of soil is worse, the settlement and non-uniform settlement of buildings increase, meanwhile P1 and E1 increase. With the increasing story of the framework, the settlement of building is nearly not affected, and P1 and E1 decrease slightly.