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Journal articles on the topic 'Cofferdams'

Author: Grafiati

Published: 4 June 2021

Last updated: 3 March 2023

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1

Madanayaka, Thushara Asela, and Nagaratnam Sivakugan. "Simple solutions for square and rectangular cofferdam seepage problems." Canadian Geotechnical Journal 56, no. 5 (May 2019): 730–45. http://dx.doi.org/10.1139/cgj-2018-0295.

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Cofferdams are widely used temporary structures at construction sites. Two of the main parameters required in designing a cofferdam are the flow rate and exit hydraulic gradient at the bottom of the excavation. Commonly, these two parameters are evaluated by using two-dimensional (2D) ground water flow models. However, when the flow pattern is three-dimensional (3D), such as flow into the square or rectangular cofferdams, predictions by the 2D models underestimate the flow rate and exit gradients considerably. Therefore, it is necessary to incorporate the 3D flow effect through a correction factor. It is shown that treating a square cofferdam as a circular one of the same width or treating a rectangular cofferdam as a 2D double-walled cofferdam significantly underestimates the flow rate. In this study, simple expressions are developed and validated for accurately estimating the flow rate and exit hydraulic gradient values of square and rectangular cofferdams, based on hundreds of finite element simulations in both 2D and 3D. It is suggested that the expressions given in the Canadian foundation engineering manual be improved.

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2

Zhao, Chun Ju, Yi Hong Zhou, and Hong Min Guo. "Experimental Study on Flood Control during Construction for Jinping II Hydropower Station." Applied Mechanics and Materials 212-213 (October 2012): 772–79. http://dx.doi.org/10.4028/www.scientific.net/amm.212-213.772.

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Jingping II hydropower project is a diversion type hydropower station with low dam, long tunnel and large capacity. Cofferdams are set to retain water flow which will be diverted through a single tunnel during dry seasons, yet be designed to allow controlled flooding during flood seasons. A physical model is built to study the hydraulic features during flooding process. Then the velocity distribution at critical positions over the overtopped earth-rock cofferdams is tested under design flux and other working conditions, as well as other hydraulic parameters such as press distribution over cofferdam slopes. Moreover, the flow regime over cofferdams is observed, and then the section forms of cofferdams are optimized to ensure the safely passing of flood during construction.

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3

Liu, Ai Min, and Shu Wang Yan. "New Construction Method of Marine Cofferdam on the Soft Ground in Tideland." Advanced Materials Research 446-449 (January 2012): 1785–90. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.1785.

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The marine cofferdams of the littoral new town in Lianyungang were constructed with geotextile bags filled with solidified soil and the soft ground under the cofferdams was treated by under water vacuum preloading method. The dimension of the cofferdams was reduced while the foundation kept stable. And the cofferdams were configurated with the geotextile bags filled with solidified soil, the silt clay was utilized adequately, the sand stone resource was saved and protected, the obvious effect was achieved. This method can be promoted in construction of marine cofferdams.

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4

Bensmaine, Aissa, Naima Benmebarek, and Sadok Bensmebarek. "Numerical Analysis of Seepage Failure Modes of Sandy Soils within a Cylindrical Cofferdam." Civil Engineering Journal 8, no. 7 (July 1, 2022): 1388–405. http://dx.doi.org/10.28991/cej-2022-08-07-06.

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Soil seepage failure within cofferdams is a dangerous phenomenon that always poses difficulties for designers and builders of excavations in zones with high water levels. When the hydraulic head difference H between the upstream and downstream sides reaches a critical height, the downstream soil seepage failure occurs. Depending on soil properties, soil-wall interface characteristics, and cofferdam design, different seepage failure modes can be observed: heaving, boiling, liquefaction, or failure by reduction of the passive earth pressure. In the literature, there are differences, sometimes very large, in the critical value of the hydraulic head loss Hc/D inducing seepage failure given by several methods proposed for stability verification. Then, complex cases are generally approached using simplifying assumptions and adopting large safety factors to take account of uncertainties. In practice, geotechnical engineers deal with many kinds of excavations and different shapes of cofferdams, such as rectangular, square, or circular, which generate three-dimensional (3D) flow conditions. Axisymmetric seepage flow through the soil in a circular cofferdam is often used to model such 3D seepage flow. In this paper, using the numerical code FLAC, several numerical simulations are carried out in axisymmetric groundwater flow conditions to analyze the seepage failure modes of cohesionless sandy soils within a cylindrical cofferdam. The effects of the cofferdam radius, internal soil friction, soil dilatancy, and interface friction on the Hc/D value and failure mode are studied. The numerically obtained seepage failure modes are presented and discussed in various scenarios. The present results, illustrated in both tables and graphs, show a significant decrease in the value of Hc/Dinducing seepage failure, with a decrease in the cofferdam radius. They also indicate the sensitivity of the seepage failure mode to internal soil friction, soil dilatancy, interface friction, and cofferdam radius. As well, new terms are proposed for the seepage failure mode designations based on the 3D view of the downstream soil deformation. Doi: 10.28991/CEJ-2022-08-07-06 Full Text: PDF

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5

Cui, Chun Yi, Zhong Tao Wang, and Jian Huang. "Dynamic Analysis of Response of Cofferdam with Steel Sheet Piles Induced by Earthquake Excitation." Applied Mechanics and Materials 117-119 (October 2011): 695–98. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.695.

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For its construction convenience and structure integrity, cofferdams are widely employed in port engineering. Past experience has shown that cofferdam are subjected to damage due to earthquake excitations. Numerical analyses with both response spectrum and step-by-step integration methods are conducted by using Lanczos eigenvalue extraction technique to obtain natural frequencies and modes, and solving dynamic equations with Newmark implicit method to consider geometric nonlinearity. The computational results show that the natural frequency of cofferdam system is low and the horizontal translation stiffness of cofferdam in positive direction is higher than that in negative direction. Under seismic excitation, the displacement response of inner steel sheet is much more obvious than that of outer one. And the distribution of horizontal displacements in steel sheets presents the characteristics that the corresponding values increase with their heights in the cofferdam system. On the contrary, the deviatonic stresses of cofferdam decrease with the augments of height.

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6

Alfatlawi, Thair J. M., Nassrin J. AL Mansori, and Riyadh A. A. Alsultani. "Stability Assessment of Diaphram Cellular Cofferdams Subjected to Severe Hydro-structural Conditions." Open Civil Engineering Journal 14, no. 1 (March 20, 2020): 44–55. http://dx.doi.org/10.2174/1874149502014010044.

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Background: Cellular cofferdams are a temporary construction consisting of interlocking steel sheet pilings driven into the ground as a series of interconnecting cells. Objectives: This study aims to investigate the stability of cofferdams with a circular diaphragm due to lateral load in dry and wet soil cases. Discussion: A series of laboratory tests were performed on different width to height ratios (0.8, 0.9, and 1.0), berm ratios (0.2H, 0.3H, and 0.4H), and embedment depth ratios (0.2H, 0.3H, and 0.4H) with four types of soil fill (clay soil, river sand, sand passing sieve No.4, and sub base). The coupled circular cofferdam-soil system was modelled using nonlinear finite element analysis (COMSOL Multiphysics Software) to validate the experimental results. Conclusion: After applying hydrostatic, hydrodynamic, and structural failure loads, the resistance of the cellular retaining structures with wet soil fill in saturated soils was greater than with dry soil fill in dry soils. The most advantageous construction format was found by deciphering the relationship between the aforementioned loads and berm ratios, embedment depth, and horizontal displacement.

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7

Chen, Shi, Yixian Wang, Yonghai Li, Xian Li, Panpan Guo, Weichao Hou, and Yan Liu. "Deformation and Force Analysis of Wood-Piled Island Cofferdam Based on Equivalent Bending Stiffness Principle." Buildings 12, no. 8 (July 27, 2022): 1104. http://dx.doi.org/10.3390/buildings12081104.

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This paper analyses the deformation and force behavior of a wood-piled island cofferdam based on the principle of equivalent bending stiffness. The horizontal deformation and bending moments in wood piles and the axial stress in tension bars on top of piles were both analyzed by the finite difference (FD) method. Except for the analysis of the cofferdam construction process, the influence of the pile length, the dam width, the tension bar interval, and the pile interval, among the commonly adopted parameters, were detailly examined in numerical simulations. In addition, a reinforced wood-piled cofferdam model by steel pipe piles has been established to quantify the effect of reinforcement. It was found that the dewatering inside the cofferdam was detrimental to cofferdam stability. The pile deformation reached maxima (roughly 0.6% of the pile length) at solidifying stage after dewatering. The changing trend of the cofferdam structure force within a safe district was consistent with the displacement. The dam width had a vital effect on the stability of the cofferdam, especially on the horizontal deformation. The steel pipe pile reinforcement scheme performed better in further deformation control, providing a new idea for island-type cofferdams with rigorous structural deformation control.

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8

Griffiths, D. V. "Seepage beneath unsymmetric cofferdams." Géotechnique 44, no. 2 (June 1994): 297–305. http://dx.doi.org/10.1680/geot.1994.44.2.297.

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9

King, G. J. W. "Design charts for long cofferdams." Géotechnique 40, no. 4 (December 1990): 647–50. http://dx.doi.org/10.1680/geot.1990.40.4.647.

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10

Banerjee, Sunirmal. "Design Charts for Double‐Walled Cofferdams." Journal of Geotechnical Engineering 119, no. 2 (February 1993): 214–22. http://dx.doi.org/10.1061/(asce)0733-9410(1993)119:2(214).

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11

Verstov, V. V., A. F. Yudina, and A. N. Gaido. "Improving Efficiency of Arranging Offshore Cofferdams." Soil Mechanics and Foundation Engineering 57, no. 1 (March 2020): 73–76. http://dx.doi.org/10.1007/s11204-020-09639-2.

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12

Tang, Long, Bo Li, Bin Zhao, Peng Li, Zhanbin Li, and Yang Gao. "Invasive Smooth Cordgrass (Spartina alterniflora) Eradication and Native Crab Recovery." Invasive Plant Science and Management 11, no. 2 (June 2018): 89–95. http://dx.doi.org/10.1017/inp.2018.13.

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AbstractInvasive smooth cordgrass (Spartina alterniflora Loisel) eradication is important for the health of many coastal ecosystems. An integrated regime of continuous submergence after clear mowing, with three interval levels between mowing and submergence (5, 10, and 15 d) and three submergence depths (20, 30, and 50 cm), was implemented in cofferdams enclosing invader populations along a Chinese coast. In July of the following year, after the roots of mowed S. alterniflora had been submerged for 12 mo, some ramets grew under the regime with an interval of 15 d and the regime with a submergence depth of 20 cm, but no ramets occurred under the regimes with submergence depths of 30 or 50 cm and intervals of 5 or 10 d. Four crab species were documented: Helice tridens tientsinensis Rathbun, Sesarma dehaani H. Milne-Edwards, Ocypode stimpsoni Ortmann, and Chiromantes haematocheir de Haan. Biomass and abundance values of crab species in the cofferdams were similar to those in the mudflats but different from those in smooth cordgrass populations. Thus, the treatment of submergence after mowing, which was implemented in the cofferdams, can control S. alterniflora and provide a mudflat-like habitat that promotes crab recovery if this treatment uses the proper combination of submergence depth and interval between mowing and submergence.

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13

Davydov, S. A. "Elimination of cofferdams when constructing hydroelectric stations." Hydrotechnical Construction 22, no. 8 (August 1988): 463–67. http://dx.doi.org/10.1007/bf01432214.

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14

Zhao, Xin, and Yunlong He. "The Permeable Character of CSG Dams and Their Seepage Fields." Complexity 2018 (October 14, 2018): 1–14. http://dx.doi.org/10.1155/2018/6498458.

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Current studies regarding the permeable properties, corrosion properties, and seepage characteristics of cemented sand and gravel (CSG) materials are based on laboratory tests. Thus, there is a lack of studies analyzing the permeable character of seepage fields based on monitoring data from real prototypes working under practical operating conditions. In this paper, on the basis of measured data from the Dahuaqiao cofferdam, we establish an inversion analysis method for unsteady seepage fields covering different time periods within a time sequence. The results indicate an effective dynamic change law for the material permeability coefficient and the real dynamic evolution characteristics of seepage fields. The permeability coefficient of CSG exhibits a “self-healing” phenomenon similar to concrete, with the seepage characteristics of a dam tending to become stable over time. Under the long-term action of water pressure, the seepage behavior of the dam body shows no obvious deterioration, suggesting that CSG can satisfy the required anticorrosion property expected of dam construction materials. Thus, abnormal CSG might serve as an effective antiseepage layer that can meet the running requirements of cofferdams. The results of this research can provide reference for further improvement in the CSG dam design theory.

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15

Yanmaz, A. Melih. "Overtopping risk assessment in river diversion facility design." Canadian Journal of Civil Engineering 27, no. 2 (April 1, 2000): 319–26. http://dx.doi.org/10.1139/l99-074.

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Diversion canals supplemented with upstream and downstream cofferdams are constructed to divert river flow for the construction of diversion weirs. Insufficient canal capacity leads to overtopping of water from the crest of the upstream cofferdam and sides of the diversion canal, which is regarded as the dominant risk mode in the system. A dynamic reliability model, which is based on a resistance-loading methodology with random independent loading following a Poisson process and random fixed resistance, may be used to assess the risk levels for various return periods and construction duration of a diversion weir. The system resistance is considered as the maximum canal capacity described by a lognormal probability density function. The river flow rate corresponding to a certain return period is considered as the external loading on the system. In a case study, a dynamic reliability analysis is performed for a diversion facility. From a flood flow frequency analysis, log-Pearson type 3 distribution is selected to describe the loading. The relationships between the total cost of the diversion facility, its reliability, safety, and duration of construction are examined in a decision making framework.Key words: dynamic reliability, diversion facility, resistance, loading.

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16

Song, Zida, Quan Liu, Zhigen Hu, Chunsheng Zhang, Jinming Ren, Zhexin Wang, and Jianhai Tian. "Construction Diversion Risk Assessment for Hydropower Development on Sediment-Rich Rivers." Energies 13, no. 4 (February 19, 2020): 938. http://dx.doi.org/10.3390/en13040938.

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Hydropower is an important renewable energy, and Construction Diversion Risk (CDR) should be highlighted and assessed during hydropower development. Since sediment-rich rivers are widely existing around the world and have great hydro-energy potential, assessing CDR for hydropower development on sediment-rich rivers in terms of engineering feasibility is of significance. This paper proposes a CDR assessment method for the sediment-rich hydropower development environment. The method is concise and practical, reflects diversion uncertainties and correlation, and mainly adopts the Gumbel–Hougaard Copula and the Monte Carlo Simulation. Through simulating flood evolution and sediment impact during diversion, the method can assess CDR basing on the cofferdam overtopping probability. Case results show that the proposed method can achieve CDR assessment on a sediment-rich river and highlights sediment impact on the diversion risk. Through results discussion, the risk feature of construction diversion on sediment-rich rivers is revealed, that sediment impact causes the dynamic and yearly-risen CDR. Hence, our conclusions are: (1) the proposed method is feasible, effective and has industrial potential, and (2) a diversion scheme on sediment-rich rivers is suggested that adopts the design with high or yearly-heightening cofferdams, based on the advanced CDR assessment to cope with the risk features of sediment-rich diversion environments.

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17

Banerjee, Sunirmal, and Angel Muleshkov. "Analytical Solution of Steady Seepage Into Double‐Walled Cofferdams." Journal of Engineering Mechanics 118, no. 3 (March 1992): 525–39. http://dx.doi.org/10.1061/(asce)0733-9399(1992)118:3(525).

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18

Rossow, M. P., and R. L. Mosher. "Design of cellular cofferdams by the ccell computer program." Computers & Structures 42, no. 6 (March 1992): 979–88. http://dx.doi.org/10.1016/0045-7949(92)90108-c.

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19

Xue, Runze, Shean Bie, Linlin Guo, and Peiliang Zhang. "Stability Analysis for Cofferdams of Pile Wall Frame Structures." KSCE Journal of Civil Engineering 23, no. 9 (August 6, 2019): 4010–21. http://dx.doi.org/10.1007/s12205-019-1320-7.

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20

Chen, Linya, Dong-Sheng Jeng, Chencong Liao, and Dagui Tong. "Wave-Induced Seabed Response around a Dumbbell Cofferdam in Non-Homogeneous Anisotropic Seabed." Journal of Marine Science and Engineering 7, no. 6 (June 19, 2019): 189. http://dx.doi.org/10.3390/jmse7060189.

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Cofferdams are frequently used to assist in the construction of offshore structures that are built on a natural non-homogeneous anisotropic seabed. In this study, a three-dimensional (3D) integrated numerical model consisting of a wave submodel and seabed submodel was adopted to investigate the wave–structure–seabed interaction. Reynolds-Averaged Navier–Stokes (RANS) equations were employed to simulate the wave-induced fluid motion and Biot’s poroelastic theory was adopted to control the wave-induced seabed response. The present model was validated with available laboratory experimental data and previous analytical results. The hydrodynamic process and seabed response around the dumbbell cofferdam are discussed in detail, with particular attention paid to the influence of the depth functions of the permeability K i and shear modulus G j . Numerical results indicate that to avoid the misestimation of the liquefaction depth, a steady-state analysis should be carried out prior to the transient seabed response analysis to first determine the equilibrium state caused by seabed consolidation. The depth function G j markedly affects the vertical distribution of the pore pressure and the seabed liquefaction around the dumbbell cofferdam. The depth function K i has a mild effect on the vertical distribution of the pore pressure within a coarse sand seabed, with the influence concentrated in the range defined by 0.1 times the seabed thickness above and below the embedded depth. The depth function K i has little effect on seabed liquefaction. In addition, the traditional assumption that treats the seabed parameters as constants may result in the overestimation of the seabed liquefaction depth and the liquefaction area around the cofferdam will be miscalculated if consolidation is not considered. Moreover, parametric studies reveal that the shear modulus at the seabed surface G z 0 has a significant influence on the vertical distribution of the pore pressure. However, the effect of the permeability at the seabed surface K z 0 on the vertical distribution of the pore pressure is mainly concentrated on the seabed above the embedded depth in front and to the side of the cofferdam. Furthermore, the amplitude of pore pressure decreases as Poisson’s ratio μ s increases.

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21

Buhan, P. de, and A. Corfdir. "Limit Design of Axisymmetric Shells with Application to Cellular Cofferdams." Journal of Engineering Mechanics 122, no. 10 (October 1996): 921–29. http://dx.doi.org/10.1061/(asce)0733-9399(1996)122:10(921).

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22

Sembenelli, P. Groppo, and G. Sembenelli. "Deep Jet-Grouted Cut-Offs in Riverine Alluvia for Ertan Cofferdams." Journal of Geotechnical and Geoenvironmental Engineering 125, no. 2 (February 1999): 142–53. http://dx.doi.org/10.1061/(asce)1090-0241(1999)125:2(142).

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23

Menshikov, PV, VA Kutuev, and SN Zharikov. "Shock wave analysis: A case-study of Magnezitovaya Mine." IOP Conference Series: Earth and Environmental Science 991, no. 1 (February 1, 2022): 012045. http://dx.doi.org/10.1088/1755-1315/991/1/012045.

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Abstract The article presents the studies into the impact of shock waves induced by underground blasting. The instrumental measurement of actual pressures at the shock wave front in air in Magnezitovaya Mine during blasting is performed. Using the measurement data, the safe distances of shock wave impact out of possible personnel injury risk are determined. The excess pressure at the shock wave front in mine air is calculated with regard to local pressure losses. The calculated excess pressures are compared with the maximum allowable pressures for personnel, timber cofferdams, ventducts, appliances and power lines.

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24

Madanayaka, Thushara Asela, and Nagaratnam Sivakugan. "Validity of the Method of Fragments for Seepage Analysis in Circular Cofferdams." Geotechnical and Geological Engineering 38, no. 2 (October 31, 2019): 1547–65. http://dx.doi.org/10.1007/s10706-019-01111-9.

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25

Konoshenkov, Aleksandr Alekseevich. "FORMULATION OF CALCULATION MODEL OF GROUND COFFERDAMS DESTRUCTION IN THE EMERGENCY SPILLWAY." Vestnik Gosudarstvennogo universiteta morskogo i rechnogo flota imeni admirala S. O. Makarova 8, no. 4 (August 31, 2016): 94–104. http://dx.doi.org/10.21821/2309-5180-2016-8-4-94-104.

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26

Verstov, V. V., A. N. Gaydo, and Ya A. Turkevich. "Improvement of technological schemes and parameters of soil extraction at submerging the cofferdams." Вестник гражданских инженеров 15, no. 5 (2018): 84–93. http://dx.doi.org/10.23968/1999-5571-2018-15-5-84-93.

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27

Arboleda-Monsalve, Luis G., A. Felipe Uribe-Henao, Alejandro Velásquez-Pérez, David G. Zapata-Medina, and Fernando Sarabia. "Performance of Urban Cofferdams Braced with Segmental Steel and Reinforced Concrete Ring Beams." Journal of Geotechnical and Geoenvironmental Engineering 144, no. 4 (April 2018): 04018015. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0001864.

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28

Hou, Jin Fang, Ju Chen, and Xiao Qiang Kou. "Numerical Analysis of Soft Soil Ground Consolidation Settlement." Applied Mechanics and Materials 638-640 (September 2014): 503–6. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.503.

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An artificial island under construction is located at an open sea and constructed by such a way that island walls are composed of steel cofferdams inserted into impermeable layers and then filled with sands. Grounds on the island are covered by thick soft soil layers with high water content, large compressibility and low bearing capacity, and treated by a jointed dewatering surcharge preloading method. In order to know the settlement property of the soft soil ground, the numerical analysis is implemented. During the analyzing, the parameters are adjusted and calculated through inverse analysis compared with practical measured data. So the numerical calculation results are more reliable. The analysis results indicate that the residual settlement of the soft soil ground is 9cm, and main ground consolidation settlement will be completed for two years after construction finished.

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29

Kowalski, Kurt P., Douglas A. Wilcox, and Michael J. Wiley. "Stimulating a Great Lakes coastal wetland seed bank using portable cofferdams: implications for habitat rehabilitation." Journal of Great Lakes Research 35, no. 2 (June 2009): 206–14. http://dx.doi.org/10.1016/j.jglr.2008.12.005.

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30

Wang, Haobin, Dandan Xu, Dong Zhang, Yihan Pu, and Zhaoqing Luan. "Shoreline Dynamics of Chongming Island and Driving Factor Analysis Based on Landsat Images." Remote Sensing 14, no. 14 (July 8, 2022): 3305. http://dx.doi.org/10.3390/rs14143305.

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Chongming Island, the third largest island in China, has experienced dramatic shoreline changes due to erosion, river deposits, and human activities. While previous studies have shown the capacity of Landsat series images to extract shoreline dynamics, the spatial variation of shoreline dynamics and their corresponding driving factors remain unclear. Therefore, we established a method to monitor the shoreline dynamics of Chongming Island from 1984 to 2020 and to evaluate the driving factors of shoreline changes using a novel approach to Landsat image analysis. The method, based on the LISA (local indicator of spatial autocorrelation) concept, automatically extracted the shoreline from Landsat imagery. The results show that the LISA method, based on the SWIR1 band, has a high capacity for shoreline extraction in Chongming Island. By distinguishing the responses of the eastern and northern shorelines to upstream sediment loads and comprehensively analyzing the driving factors of eastern and northern dynamics, we found that: (i) although upstream sediment loads decreased dramatically, the shoreline of Chongming Island is still expanding due to human activities (i.e., reclamation and an estuary project) and sediment re-suspension from near-shore or cross-shore currents; (ii) the expansion of Chongming Island was initially due to the dynamics at the eastern shoreline, but the expansion of the eastern shoreline slowed after 2008 as upstream sedimentation slowed, less construction of cofferdams took place, and the Qingcaosha Reservoir was constructed; (iii) the northern shoreline of Chongming Island expanded rapidly after 1999, due to the merger of Xinlongsha, Xincunsha, and Chongming Island, and the transport of coastal and offshore sediments by hydrodynamic processes; and (iv) the main driving factors of eastern shoreline movement on Chongming Island are cofferdam reclamation and coastal engineering, and the changes at the northern shoreline are mainly affected by reclamation projects, offshore sediment supplies, and upstream sediment inflow. The results of this study provide theoretical fundamentals for land reclamation and future urban planning for Chongming Island.

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31

Hardyniec, Sara, and Sarah Skeen. "Pile Driving and Barotrauma Effects." Transportation Research Record: Journal of the Transportation Research Board 1941, no. 1 (January 2005): 184–90. http://dx.doi.org/10.1177/0361198105194100124.

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High-capacity driven pipe piles have recently been shown to be a viable alternative to pile groups in terms of economy and strength. A complication has emerged for the construction of bridge foundations with large-diameter pipe piles, however–-the injury and mortality of fish from sound pressure waves produced from pile driving, otherwise known as barotrauma. Even though this issue has been prevalent in California, regulators have started to restrict other states. This has caused confusion as to how to avoid unexpected increases in construction costs while following environmental laws. After several trials, California Department of Transportation (Caltrans) engineers have implemented solutions to this problem, including driving windows, cofferdams, and a few different versions of air bubble curtains. This paper presents an accumulation of knowledge from engineers, biologists, and sound experts. It is to serve as an avenue for informing those who may soon be affected with pile-driving and fish barotrauma issues to minimize harmful effects and costs in the future.

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32

Zhang, Libin, Hongsheng Yang, Qiang Xu, Kun Xing, Peng Zhao, and Chenggang Lin. "A new system for the culture and stock enhancement of sea cucumber, Apostichopus japonicus (Selenka),in cofferdams." Aquaculture Research 42, no. 10 (January 4, 2011): 1431–39. http://dx.doi.org/10.1111/j.1365-2109.2010.02735.x.

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33

Schroeder, W. L. "Discussion of “ Sheetpile Interlock Tension in Cellular Cofferdams ” by Mark P. Rossow (October, 1984, Vol. 110, No. 10)." Journal of Geotechnical Engineering 113, no. 5 (May 1987): 547–49. http://dx.doi.org/10.1061/(asce)0733-9410(1987)113:5(547).

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34

Rossow, Mark P. "Closure to “ Sheetpile Interlock Tension in Cellular Cofferdams ” by Mark P. Rossow (October, 1984, Vol. 110, No. 10)." Journal of Geotechnical Engineering 113, no. 5 (May 1987): 549–50. http://dx.doi.org/10.1061/(asce)0733-9410(1987)113:5(549).

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35

Shao, Junhu, Zihao Fan, Yuanyuan Huang, Yulin Zhan, and Qinhao Cai. "Multi-objective optimization of double-walled steel cofferdams based on response surface methodology and particle swarm optimization algorithm." Structures 49 (March 2023): 256–66. http://dx.doi.org/10.1016/j.istruc.2023.01.092.

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36

Callari, Carlo, and Francesco Froiio. "A HYDROMECHANICAL FINITE ELEMENT FORMULATION FOR LOCALIZED INTERNAL EROSION IN POROUS MEDIA, WITH APPLICATION TO BACKWARD PIPING IN COFFERDAMS." International Journal for Multiscale Computational Engineering 18, no. 2 (2020): 181–97. http://dx.doi.org/10.1615/intjmultcompeng.2020031422.

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37

Vozbrannaya, Anna, Vladimir Antipin, and Andrey Sirin. "After Wildfires and Rewetting: Results of 15+ Years’ Monitoring of Vegetation and Environmental Factors in Cutover Peatland." Diversity 15, no. 1 (December 20, 2022): 3. http://dx.doi.org/10.3390/d15010003.

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On examples of n × 100 m2 permanent plots laid in 2005 on peatlands disturbed by quarrying and milling peat extraction in Meshchera National Park (central European Russia), changes in vegetation cover and environmental factors during self-revegetation, the impact of wildfire, and rewetting are considered. Peat extraction pits are overgrown with floating mats, on which mire, predominantly mesotrophic, vegetation is formed. Cofferdams with retained original mire vegetation contribute to the formation of a spatially diverse mire landscape, but they can also be prone to natural fires. The environmental conditions at the abandoned milled peat extraction sites do not favour natural overgrowth. The driest areas can remain with bare peat perennially. Such peatlands are the most frequent targets of wildfires, which have a severely negative impact and interrupt revegetation processes. Alien plant species emerge and disappear over time. To prevent wildfires and create conditions favourable for the restoration of mire vegetation, rewetting is required. With an average ground water level (GWL) during the growing season of −5 to +15 cm, mire vegetation can actively re-establish. Communities with near-aquatic and aquatic plants can form on flooded areas with GWL of +30. This generally contributes to both fire prevention and wetland diversity.

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38

Gao, Xin, Liqiang Sun, Wei Guo, Ruxiao Ren, and Wenqian Zeng. "Overturning stability of supported geomembrane tube for flood control." E3S Web of Conferences 283 (2021): 02044. http://dx.doi.org/10.1051/e3sconf/202128302044.

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As a kind of rapid filling hydraulic structure, geomembrane tube can effectively act as flood barriers and cofferdams for flood risk management. L-shaped block is used to support geomembrane tube to prevent it from rolling. The contact force between the L-shaped block and the geomembrane tube is analyzed by using particle flow code (PFC2D) software, and the overturning stability of the L-shaped block is calculated. The relationship between the key factors and the overturning stability was established. It is found that the central angle of the L-shaped block has little influence on the overturning stability. The overturning stability decreases with the increase of the initial pumping pressure. Keeping Lw/Lb unchanged, increasing Lb will improve the overturning stability where Lw and Lb are the width and the height of the Lshaped block. Under the ultimate water level, when 1.23 Lbcr < Lw≤1.55 Lbcr, the L-shaped block is in the state of overturning stability where Lbcr is the critical height of the L-shaped block. The initial pumping pressure is less than 0.152γL, the L-shaped block is in the state of overturning stability with Lw/Lbcr =1.0 where L is the cross-sectional perimeter of the geomembrane tube and γ is the unit weight of the filling liquid, on the contrary, Lw/Lbcr must be greater than 1 to ensure its overturning stability.

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39

Shishkonakova, E. A., N. A. Avetov, G. V. Vindeker, T. Yu Tolpysheva, and N. R. Garaeva. "Soil- and biodiversity of the former peat mines in Shaturskaya Meshchera in the context of their anthropogenic transformation." Dokuchaev Soil Bulletin, no. 111 (September 25, 2022): 30–76. http://dx.doi.org/10.19047/0136-1694-2022-111-30-76.

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The problem of pedo- and biodiversity of mire ecosystems under the long-term multiple anthropogenic impact was studied in one of the most intensively technogenically transformed areas of Shaturskaya Meshchera, adjacent to power station Shaturskaya in the north and stretching along the route Kerva – Dolgusha – Severnaya Griva. For more than a hundred years, mires in the Shatura area have been under the influence of drainage, peat extraction, fires, attempts to create agricultural land, secondary watering and pollution, resulting from the power station, transport, and settlements wastewaters. Currently, the bio- and soil diversity of secondary ecosystems has increased significantly compared to undisturbed mires. Instead of bog, in some cases there appeared secondary meadow, grass-shrub communities, small-leaved forests, and dry sparse areas. The remaining bogs experience stable eutrophication, which leads to the formation of mesotrophic and eutrophic phytocenoses and, accordingly, peat mesotrophic and oligotrophic secondary eutrophic soils. In addition, the proportion of eutrophic mires is slightly increased by the peat formation in shallow lakes, which at the initial stage of peat extraction were used for storing wood waste. The phenomenon of secondary oligotrophization of the disturbed bogs of Meshchera, noted in the literature, is not observed in the area under consideration due to a significant anthropogenic load. To preserve the local flora of oligotrophic bogs, marginal areas of flooded quarries and cofferdams with undeveloped peat deposits are of great importance. The increase in pedodiversity was facilitated by the agricultural development of drained peatlands for the cultivation of perennial grasses, which resulted in the formation of torfozems and agrotorfyano-gleyzems.

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40

Callicutt, Edwin. "Special-Design Precast Concrete Beams for Sidney Lanier Bridge Replacement Project." Transportation Research Record: Journal of the Transportation Research Board 1696, no. 1 (January 2000): 48–51. http://dx.doi.org/10.3141/1696-07.

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The Sidney Lanier Bridge Replacement Project is a $100 million undertaking in Brunswick, Georgia, that will lead to the replacement of an existing 40-year-old steel lift-span structure. The approach bridges that lead to the project’s main-span unit consist of 16 spans of 54.9-m (180-ft), special-design, precast concrete beams as well as 14 spans of 36.6-m (120-ft) Type V AASHTO girders. The special-design beams are 2.3 m (7.5 ft) deep, are erected as simply supported members and are then made into two-span continuous units by longitudinal posttensioning, and are rigidly connected transversely with cast-in-place diaphragms. The riding surface is a cast-in-place concrete deck constructed on stay-in-place metal forms. The 54.9-m (180-ft) beams, supported by hollow tapered concrete piers with hammerhead caps, are founded on 1.2-m (48-in.) drilled shafts. Wet-hole construction methods with bentonite slurry were required for the drilled shafts. The bridge piers are over land and water, and large cofferdams were required to facilitate construction. Additionally, the sizes of the cast-in-place footings and hammerhead pier caps required mass concrete thermal considerations. The approach bridges lead to the main-span portion of the project, which will be a 762-m (2,500-ft) concrete, cable-stayed unit with a 381-m (1,250-ft) center span. The design, casting, and erection of these beams, and construction of the substructure, posed many challenges to the Georgia Department of Transportation designers and contractors. These beams are among the longest erected in Georgia.

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41

Jeong, Youn-Ju, Jeong-Soo Kim, Min-Su Park, and Sung-Hoon Song. "HYDRODYNAMIC BEHAVIORS OF LARGE STEEL-CYLINDRICAL COFFERDAM SYSTEM FOR MARINE STRUCTURES CONSTRUCTION." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 26. http://dx.doi.org/10.9753/icce.v36.structures.26.

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Some cofferdam systems have been applied for marine structures construction of bridges, marine foundation, and etc. Recently, new cofferdam system using large steel-cylindrical members proposed to reduce marine working periods and to improve economic of marine working. In order to construct marine cofferdam system with large steel-cylindrical members, (step 1) some modules composing of a large steel-cylindrical cofferdam system fabricate with typical height in steel factory, and (step 2) move to the construction site onto the barge towing. Then, (step 3) large steel-cylindrical cofferdam system completes by module to module connection with vertical direction in seawater. Finally, (step 4) inside water of large steel-cylindrical cofferdam draw out by pumping, and (step 5) the marine structures are constructed under land based conditions. This cofferdam system has advantages to reduce marine working period and to secure structural safety uniformly.

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42

,, Yunaefi. "SECANT PILE SEBAGAI PENAHAN REMBESAN DI COFFERDAM (STUDI KASUS PADA PROYEK DERMAGA LAMONGAN)." PROKONS Jurusan Teknik Sipil 7, no. 2 (August 31, 2013): 111. http://dx.doi.org/10.33795/prokons.v7i2.43.

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Dalam pembangunan pantai Lamongan yang terletak pada genangan air laut perlu digunakan timbunan batuan boulder, pedel, dan urukan tanah sebagai cofferdam. Struktur sementara tersebut dibuat sebagai struktur penahan/ membendung air untuk melindungi pekerjaan galian pondasi dermaga. Karena tekanan air laut cukup besar pasti akan menimbulkan rembesan yang nantinya menggenangi area pekerjaan pembuatan dermagaUntuk mengurangi rembesan tersebut perlu adanya perkuatan timbunan (cofferdam), sehingga pada konstruksi cofferdam diperkuat dengan secant pile. Dalam perencanaan secant pile sebagai penahan rembesan di cofferdam pada proyek dermaga Lamongan dilakukan perhitungan menggunakan pedoman konstuksi dan bangunan Departemen Pekerjaan Umum.Dari perhitungan tersebut didapat diameter secant pile 600 mm, kedalaman secant pile antara 10-24 m, mutu beton K -125, dan mutu besi tulangan 400 MPa. Dengan adanya secant pile sebagai cofferdam pada proyek dermaga pantai Lamongan diharap dapat mengurangi rembesan pada cofferdam sehingga memperlancar pekerjaan proyek dermaga. Kata-kata kunci: cofferdam, dermaga, secant pile, rembesan, timbunan

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43

Xiong, Bao Lin, Jin Song Tang, and Wei Chen. "Inside and Outside Earth Pressure Research of Steel Sheet Pile Cofferdam." Advanced Materials Research 446-449 (January 2012): 1822–26. http://dx.doi.org/10.4028/www.scientific.net/amr.446-449.1822.

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As the cofferdam makes the water flow change, the river bed near the cofferdam has been washed; soil pressure on the cofferdam will be changed. In order to better grasp the force of the cofferdam, the earth pressure on the cofferdam need to be monitored. As it is difficult to monitor occasion, the computing earth pressure is necessary. In this paper, three-dimensional finite element model on the steel sheet pile, purlin, internal support and soil can be established. Through compassion computing value of model and monitoring value, conclusions are drawn.

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44

Liu, Hai Wei, Fa Ning Dang, and Yi Min. "Study on Stress and Deformation of Earth-Rock Cofferdam and Concrete Cutoff Wall on Deep Overburden." Applied Mechanics and Materials 256-259 (December 2012): 383–87. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.383.

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The earth-rock cofferdam on deep overburden is the main study object. The cofferdam filling and dam excavation process were numerical simulated using FEM code ANSYS .Main research focused on stress and deformation characteristic of cofferdam and concrete cutoff wall during completion and excavation process.Analysis showed that displacements of cofferdam and cutoff wall distribute well in x, y, z directions with acceptable magnitude, stress characteristic values are less than design standard. The results indicate that cofferdam and cutoff wall are safe and stable both in construction and operation.

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45

Song, Jin Bo. "Double-Wall Cofferdam of Hero Bridge Calculation." Applied Mechanics and Materials 94-96 (September 2011): 560–63. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.560.

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Hero Bridge is an extraordinarily huge bride across northern branch Ganjiang River, in the city of Nanchang. Main tower adopted single column slanted pylon space twist face back cable structure. Its construction is based on double-wall cofferdam method. The paper discuss thecalculation of key step and key position for the key technology in terms of double-wall cofferdam and platform underwater construction, Which include the design of the base construction and double-wall cofferdam,steel cofferdam construction, the calculation and checking of the cofferdam and so on.

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46

Shi, Jian Yong, Xiang Juan Yu, and Ying Bo Ai. "Research of Hydraulic Characteristics of Cofferdam and Leaching System on Joint Way of Nanjing Second Yangtse Bridge." Applied Mechanics and Materials 353-356 (August 2013): 1040–46. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.1040.

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The hydraulic filling is the construction method of joint way in Nanjing Second Yangze Bridge. The leaching facility, drainage time and cofferdam stability in filling are key points in design. By laboratory test, the compaction, direct shear and permeability test of different compaction are investigated. The deformation through field monitor is carried during the cofferdam construction and hydraulic filling. After parameter test and stability analysis according to hydraulic filling, it is shown that the drainage ditch in base of cofferdam can satisfy drainage requirement, the leaching time is about half of one month. The compactness of cofferdam is 0.92. The slope of cofferdam during construction and hydraulic filling is in stability by analysis. And the cofferdam is in stable situation during hydraulic filling according to deformation monitoring result.

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47

Bossa, Aymar Yaovi, Jean Hounkpè, Yacouba Yira, Georges Serpantié, Bruno Lidon, Jean Louis Fusillier, Luc Olivier Sintondji, Jérôme Ebagnerin Tondoh, and Bernd Diekkrüger. "Managing New Risks of and Opportunities for the Agricultural Development of West-African Floodplains: Hydroclimatic Conditions and Implications for Rice Production." Climate 8, no. 1 (January 10, 2020): 11. http://dx.doi.org/10.3390/cli8010011.

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High rainfall events and flash flooding are becoming more frequent, leading to severe damage to crop production and water infrastructure in Burkina Faso, Western Africa. Special attention must therefore be given to the design of water control structures to ensure their flexibility and sustainability in discharging floods, while avoiding overdrainage during dry spells. This study assesses the hydroclimatic risks and implications of floodplain climate-smart rice production in southwestern Burkina Faso in order to make informed decisions regarding floodplain development. Statistical methods (Mann-Kendall test, Sen’s slope estimator, and frequency analysis) combined with rainfall-–runoff modeling (HBV model) were used to analyze the hydroclimatic conditions of the study area. Moreover, the spatial and temporal water availability for crop growth was assessed for an innovative and participatory water management technique. From 1970 to 2013, an increasing delay in the onset of the rainy season (with a decreasing pre-humid season duration) occurred, causing difficulties in predicting the onset due to the high temporal variability of rainfall in the studied region. As a result, a warming trend was observed for the past 40 years, raising questions about its negative impact on very intensive rice cultivation packages. Farmers have both positive and negative consensual perceptions of climatic hazards. The analysis of the hydrological condition of the basin through the successfully calibrated and validated hydrological HBV model indicated no significant increase in water discharge. The sowing of rice from the 10th to 30th June has been identified as optimal in order to benefit from higher surface water flows, which can be used to irrigate and meet crop water requirements during the critical flowering and grain filling phases of rice growth. Furthermore, the installation of cofferdams to increase water levels would be potentially beneficial, subject to them not hindering channel drainage during peak flow.

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48

Jiang, Ping, Yong Huang, Zhipeng Tao, Junhua Zhu, Ning Wang, and Jianwei Qiao. "Deformation Characteristics and Safety Evaluation of the Throw Filling Soft Clay Cofferdam under Super-Historical Flood Conditions." Advances in Civil Engineering 2022 (April 26, 2022): 1–10. http://dx.doi.org/10.1155/2022/9578477.

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Affected by super-historical flood, the surface deformation of throw filling soft clay cofferdam is obvious and the stability of the cofferdam slope is difficult to ensure. Relying on the cofferdam project of Jiangxi Xinjiang Shuanggang navigation power junction and according to the data of filed investigation and automatic monitoring, the Plaxis infinite element software is used to analyze the deformation characteristics and stabilities of cofferdam during the super-historical flood period, and the effective emergency reinforcement measures are presented. The results show that (1) the stability of cofferdam is controlled by downstream face slope of cofferdam during the super-historical flood period, and there is a most dangerous slide surface interpenetrating through the top to the toe of downstream face slope; (2) the stability of upstream face slope is influenced significantly by the water level fluctuation and it is reduced sharply during the water level decline process; and (3) real-time remote monitoring can effectively reflect the deformation and failure characteristics of cofferdam under the condition of super-historical flood level and provide early warning and prediction in time. The results and analyzing methods can be applied to analyze the similar projects excellently.

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49

Jiang, Ping, Yong Huang, Zhipeng Tao, Junhua Zhu, Ning Wang, and Jianwei Qiao. "Deformation Characteristics and Safety Evaluation of the Throw Filling Soft Clay Cofferdam under Super-Historical Flood Conditions." Advances in Civil Engineering 2022 (April 26, 2022): 1–10. http://dx.doi.org/10.1155/2022/9578477.

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Affected by super-historical flood, the surface deformation of throw filling soft clay cofferdam is obvious and the stability of the cofferdam slope is difficult to ensure. Relying on the cofferdam project of Jiangxi Xinjiang Shuanggang navigation power junction and according to the data of filed investigation and automatic monitoring, the Plaxis infinite element software is used to analyze the deformation characteristics and stabilities of cofferdam during the super-historical flood period, and the effective emergency reinforcement measures are presented. The results show that (1) the stability of cofferdam is controlled by downstream face slope of cofferdam during the super-historical flood period, and there is a most dangerous slide surface interpenetrating through the top to the toe of downstream face slope; (2) the stability of upstream face slope is influenced significantly by the water level fluctuation and it is reduced sharply during the water level decline process; and (3) real-time remote monitoring can effectively reflect the deformation and failure characteristics of cofferdam under the condition of super-historical flood level and provide early warning and prediction in time. The results and analyzing methods can be applied to analyze the similar projects excellently.

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50

Yuan, Yu Lin, and Yun Feng Peng. "Analysis for the Seepage Stability of the Upstream Cofferdam of One Hydropower Station." Applied Mechanics and Materials 441 (December 2013): 286–90. http://dx.doi.org/10.4028/www.scientific.net/amm.441.286.

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According to the geological conditions of upstream cofferdam and foundation of the hydropower station, analysis for the seepage of the upstream cofferdam used SEEP/W module of Geo-studio software. Analysis for the stability used SLOPE/W module with Swedish circle method and Bishop method. Safety factor of the upstream and downstream in different conditions was obtained. The results show that the design of the upstream cofferdam was reasonable, and it will provide theoretical basis for Seepage control design of cofferdam.

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