Innovative Techniques Unveiled in Advanced Sheet Pile Curtain Design

This thorough review explores the complexities of geotechnical engineering, emphasizing soil-structure interaction (SSI). The investigation centers on sheet pile design, examining two primary methodologies: Limit Equilibrium Methods (LEM) and Soil-Structure Interaction Methods (SSIM). While LEM methods, grounded in classical principles, provide valuable insights for preliminary design considerations, they may encounter limitations in addressing real-world complexities. In contrast, SSIM methods, including the SSI-SR approach, introduce precision and depth to the field. By employing numerical techniques such as Finite Element (FE) and Finite Difference (FD) analyses, these methods enable engineers to navigate the dynamics of soil-structure interaction. The exploration extends to SSI-FE, highlighting its essential role in civil engineering. By integrating Finite Element analysis with considerations for soil-structure interaction, the SSI-FE method offers a holistic understanding of how structures dynamically interact with their geotechnical environment. Throughout this exploration, the study dissects critical components governing SSIM methods, providing engineers with tools to navigate the intricate landscape of geotechnical design. The study acknowledges the significance of the Mohr-Coulomb constitutive model while recognizing its limitations, and guiding practitioners toward informed decision-making in geotechnical analyses. As the article concludes, it underscores the importance of continuous learning and innovation for the future of geotechnical engineering. With advancing technology and an evolving understanding of soil-structure interaction, the study remains committed to ensuring the safety, stability, and efficiency of geotechnical structures through cutting-edge design and analysis techniques.

Advanced Sheet Pile Curtain Design: Case Study of Cotonou East Corniche

This paper delves into the critical aspects of sheet pile walls in civil engineering, highlighting their versatility in soil protection, retention, and waterproofing, all while emphasizing sustainability and efficient construction practices. The paper explores two fundamental approaches to sheet pile design: limit equilibrium methods and numerical techniques, with a particular focus on finite element analysis. Utilizing the robust PLAXIS 2016 calculation code based on the finite element method and employing a simplified elastoplastic model (Mohr-Coulomb), this study meticulously models the interaction between sheet pile walls and surrounding soil. The research offers valuable insights into settlement and deformation patterns that adjacent buildings may experience during various construction phases. The central objective of this paper is to present the study’s findings and recommend potential mitigation measures for settlement effects on nearby structures. By unraveling the intricate interplay between sheet pile wall construction and neighboring buildings, the paper equips engineers and practitioners to make informed decisions that ensure the safety and integrity of the built environment. In the context of the Cotonou East Corniche development, the study addresses the limitations of existing software, such as RIDO, in predicting settlements and deformations affecting nearby buildings due to the substantial load supported by sheet pile walls. This information gap necessitates a comprehensive study to assess potential impacts on adjacent structures and propose suitable mitigation measures. The research underscores the intricate dynamics between sheet pile wall construction and its influence on the local environment. It emphasizes the critical importance of proactive engineering and vigilant monitoring in managing and mitigating potential hazards to nearby buildings. To mitigate these risks, the paper recommends measures such as deep foundations, ground improvement techniques, and retrofitting. The findings presented in this study contribute significantly to the field of civil engineering and offer invaluable insights into the multifaceted dynamics of construction-induced settlement. The study underscores the importance of continuous evaluation and coordination between construction teams and building owners to effectively manage the impacts of sheet pile wall construction on adjacent structures.

Improvement of Technological Solutions for Sheet Piling Walls Made of U-Shape Piles

As it is evident from the practice of construction and maintenance of thin retaining walls, the degree of developing of frictional forces in interlock connections of steel sheet U-shape piles essentially influences the realization of the values of geometric characteristics of the piles cross-section （the moment of inertia and the section modulus） reduced to the length unit of the construction. The article offers new and simple solutions for realization and economically effective technological approaches to provide joint work of the sheet piles being considered, which improve the adequacy of design and reliability of maintenance of thin retaining walls.

Leachate Control Technology Using H-Jointed Steel Pipe Sheet Piles with H-H Joints at Coastal Landfills

H-H joint of ＂H-jointed SPSP with H-H joint＂, which is made up of interlocking two H-steel sections of different sizes, is the one of SPSP＇s joint to improve the hydraulic conductivity. ＂H-H jointed SPSP with H-H joint＂ is expected to be applied to a vertical cutoff wall in coastal landfill sites. In H-jointed SPSP with H-H joint, the H-joint is completely imperviousness. H-H joint, however, is pervious at interlocked state because a gap of 8 to 11 mm is left between the interlocking flanges, therefore, a water interception treatment must be conducted to seal the gap. The water shielding treatment of H-H joint is executed by coating the gaps with a water-swelling sheet of paint before its installation. Then, hollow space is generated in H-H joint after treating by water-swelling sheet, and that space can be used effectively. This paper proposes leachate control technologies using H-H joint interior space of SPSP cutoff walls. The possibility of those technologies and hydraulic conductivity of H-jointed SPSP with H-H joints are demonstrated by conducting the hydraulic conductivity test.

FEM for Stability Analysis Against Overturning of Portal Water Injection Sheet Pile

Portal water injection sheet pile (PWISP), as a retaining wall, appeared in seashore engineering in 2000. Although there have been many systematic methods addressing the issue, there are very few focusing on the new structure because of the difficulties in defining the earth pressure between the two piles. A new method is proposed in this paper to obtain the earth pressure between the PWISPs. Stability analysis against overturning follows as a consequence. Using Finite Element Analysis (FEA) software ANSYS, both the nonlinear characteristics of the soil and those of the contact elements are taken into account to obtain the earth pressure distribution on the contact surface. Based on the results of the FEA, Rankin’s theory and the slip plane theory, the formula of the earth pressure on the inner surfaces between the piles is given. Assuming the PWISP as the analysis object and the earth pressure as an outside force acting upon it, the equation of stability against overturning of the PWISP is presented. Finally, some parameters are discussed about the stability of the PWISP against overturning, such as the embedded depth of the front pile, the distance between the two rows of piles, the internal friction angle and the cohesion of the earth. The results show that the increase of the cohesion and the internal friction angle will decrease the distance and the embedded depth, and therefore enhance the stability against overturning. Specifically, when the distance is 1/3-2/3 of the maximal excavation depth, the two rows of piles give the best performance in stability.

Seismic Response Analysis of Portal Water Injection Sheet Pile

To further the study on the newly developed portal water injection sheet pile under static loads, in this paper, by adopting the nonlinear calculation module of FEM software ANSYS, a model for the interaction between the soil and the sheet piles is set up, and the seismic response analysis for this type of space-retaining structure is performed. The effects of the embedded depth and the distance between the front pile and the back pile on the dynamic characteristics of the portal water injection sheet pile are studied.

The Influence of Water-Jet Modification of Soil Conditions on Reduction of Vibrations during Sheet Pile Driving in the Subsoil

Vibratory driving is the most efficient method of sheet pile installation. The elimination or at least reduction of harmful consequences of sheet pile vibratory driving becomes an increasingly important and often the decisive factor in the selection of the excavation protection technology. In difficult soil conditions with strength soil parameters, pressure water jetting precedes sheet pile driving. This technique changes the soil properties, destroying its existing structure near the installed sheet pile. Unfortunately, the results and achievements of contractors using this technique are very often held confidential or simply remain in the records and it is difficult to find papers on this subject. This article features a detailed description of jet-assisted sheet pile driving, including a prefabrication description for the sheet pile toe used to jet water through, water pressure and quantity data and the results with regard to reduce vibrations and noise, as well as to the increase in sheet pile vibratory driving performance.

Evaluation of Unsaturated Layer Effect on Seismic Analysis of Unbraced Sheet Pile Wall

This paper is built upon the previous developments on lateral earth pressure by providing a series of analytical expressions that may be used to evaluate vertical profiles of the effective stress and the corresponding suction stress under steady-state flow conditions. Suction stress profile is modeled for one layer sand near the ground above the water level under hydrostatic conditions. By definition, the absolute magnitude of suction stress depends on both the magnitude of the effective stress parameter and matric suction itself. Thus, by developing the Rankine’s relations in seismic state, the composing method of active and passive surfaces in sides of unbraced sheet pile is examinated and the effects of soil parameter on those surfaces are evaluated by a similar process. The relations described the quantitative evaluation of lateral earth pressure on sheet pile and the effects of unsaturated layer on bending moment and embedded depth of sheet pile in soil.

Monitoring of the Corrosion on a Steel Sheet-Pile Marine Breakwater by Systematic Thickness Measurements

In Quepos, Pacific of Costa Rica, it was finished on 2010 the first phase of a marina, including two mix breakwaters, with rubble mound （rocks and concrete units）, and 25 circular steel sheet piles cofferdam cells, filled with sand and gravel. The maintenance plan, considers tracking sheet pile corrosion, comparing ＂actual＂ against expected rates, checking structural limits, and programming countermeasures if accelerated corrosion is identified. Specific control sections, along the breakwaters, both inside and outside the basin, were established. In each section, thicknesses were measured every meter from the top of the steel cell to seabed using an ultrasonic equipment, and an underwater transducer. Both land crew, and divers for submerged portions, were used. The measurements campaigns are for several years from 2011 to 2016. Sectors of the breakwater with varied corrosion attack levels could be differentiated. Also, corrosion rates and lifespans were estimated, both general for the structures, and specific for each section and level. In turn, this allowed to identify maintenance priorities, defining sites where measures of corrosion protection should initiate, as well, to have confidence in the structural capacity and safety of the breakwaters.

Monitoring of the Corrosion on a Steel Sheet-pile Marine Breakwater by Systematic Thickness Measurements

In Quepos,Pacific of Costa Rica,it was finished on 2010 the first phase of a marina,including two mix breakwaters,with rubble mound(rocks and concrete units),and 25 circular steel sheet piles cofferdam cells,filled with sand and gravel.The maintenance plan,considers tracking sheet pile corrosion,comparing'actual'against expected rates,checking structural limits,and programming countermeasures if accelerated corrosion is identified.Specific control sections,along the breakwaters,both inside and outside the basin,were established.In each section,thicknesses were measured every meter from the top of the steel cell to seabed using an ultrasonic equipment,and an underwater transducer.Both land crew,and divers for submerged portions,were used.The measurements campaigns are for several years from 2011 to 2016.Sectors of the breakwater with varied corrosion attack levels could be differentiated.Also,corrosion rates and lifespans were estimated,both general for the structures,and specific for each section and level.In turn,this allowed to identify maintenance priorities,defining sites where measures of corrosion protection should initiate,as well,to have confidence in the structural capacity and safety of the breakwaters.

斜撑钢管板桩直立式海堤结构受力分析

某填海工程的实施可能影响邻近桥梁的安全性,拟采用斜撑钢管板桩直立式海堤结构,通过Plaxis 3D岩土有限元分析软件模拟该海堤结构的受力特性及变位,以及其对邻近桥梁桩基变位的影响。结果表明,该直立式海堤结构受力特性较好、变位较小,且对邻近桥梁桩基变位的影响较小。

格栅式钢板桩与桩筏基础集成的基坑支护技术

针对软土地质基坑工程,提出格栅式钢板桩与桩筏基础集成的基坑支护技术,通过设置纵向双排钢板桩与横向钢板桩或钢板组成格栅式钢板桩,以提高支护结构强度与刚度,并与桩筏基础协同工作,以解决结构下部软土层承载力较差的问题,并提高支护结构稳定性。以某管廊工程为依托,通过计算分析与技术对比,论证集成支护技术的安全性与可行性。

HUW组合钢板桩在软土地基深基坑工程中的 适应性分析

目的:本研究旨在分析HUW组合钢板桩在软土地基深基坑工程中的结构适应性,以期为相似地区深基坑工程提供理论支持。方法:基于某软土地区科技产业园深基坑工程,运用ABAQUS有限元软件,通过增量法模拟实际开挖过程,计算正常开挖下的结构变形和土体位移,从而分析HUW组合钢板桩在实际工程中的结构可行性。结果:随着基坑的逐层开挖,基坑边缘的沉降值逐步增大,尤其在软土地基条件下,地表沉降现象更为明显。针对6.3米深基坑的开挖,HUW组合钢板桩的最大水平位移为22.78毫米,符合基坑施工规范的要求。结论:HUW组合钢板桩在实际工程中具备可行性,可为类似工程提供理论参考。但土体受侧向约束的影响,在边界区域会形成局部隆起,因此需对边坡边缘进行加固处理。

锚索抗滑桩加固边坡震害机理分析

锚索桩板墙具有优良的抗震效果,以往研究集中于边坡位移、锚索应力和抗滑桩的变形,很少从边坡内部监测地震波入手研究,难以在时频域内清楚地表征边坡内部的损伤特征。基于此,文章设计并完成几何相似比为1∶10的大型振动台试验,结合Hilbert-Huang Transform(HHT)方法,对锚索桩板墙加固边坡进行边坡损伤诊断和震害机理研究。结果表明:边坡破坏从滑面开始,随着地震峰值加速度的增大,坡面产生破坏的时间早于坡体内部,并逐步向低高程发展;锚索桩板墙可以充分发挥锚索对地震力的传递与抗滑桩对地震力的耗散作用,靠近锚索抗滑桩一侧坡体破坏滞后于远离抗滑桩一侧,且靠近锚索桩板墙一侧土体整体性明显更好;HHT方法边际谱特征频率和特征幅值可以清晰表征坡体损伤过程,基岩与坡体之间存在动力响应不连续带,即为设计滑面位置。这为进一步认识地震波在坡体内的传播机理,研究边坡的破坏过程提供理论依据。

重力式码头升级改造板桩墙后土压力分布

针对重力式码头升级改造新建板桩墙方案板桩墙后土压力分布问题,开展新建板桩墙距已有重力式墙身不同距离的土压力分布规律研究。采用有限元数值模拟和理论公式计算对比分析,得出作用在前板桩墙上的土压力小于理论主动土压力,即存在贮仓效应的结论。建议重力式码头改造工程设置前板桩墙时,采用公式合理选取贮仓尺寸,或根据新建板桩墙距已有码头墙身的距离采用有限元计算作用在板桩墙上的土压力,避免保守或激进设计。

基于国外某矿厂码头的结构方案研究

在某矿厂码头工程设计中,利用矿厂采矿废石料回填造陆价格低廉的优势,提出了高桩梁板式结构、钢管板桩组合结构、钢管排桩结构方案并开展分析研究。在高桩梁板式方案中,为减少前方承台与后方陆域距离,采用了一种可以适应较大水深卸荷承台式接岸结构。钢管板桩组合结构和钢管排桩结构虽然均为板桩结构,但相对于钢板桩,钢管桩单桩水上可打性更好,因此分别对其采用了填筑施工围堰的陆上打桩施工方式和打桩船打桩的水上打桩施工方式。最终通过综合技术经济比选,选定了适用于本工程的最优结构方案,为提高钢排桩板桩结构的应用前景提供经验。

框架梁与锚索桩板墙加固隧道洞口边坡的动力响应特性

针对山岭隧道洞口在降雨、地震等因素作用下易产生变形破坏的问题,以某处采用框架梁与锚索桩板墙支护的隧道洞口边坡工程为原型,开展几何比尺为1∶50的振动台模型试验,分析降雨后地震作用下边坡的动力响应特性及失稳变形规律。结果表明:降雨后坡面无局部破坏,地震作用下边坡的破坏过程可归纳为坡顶张拉破坏—坡脚剪切溃裂—坡体整体失稳滑动,边坡表现为张拉—剪切型破坏;边坡峰值加速度放大系数呈层状分布,“高程效应”与“趋表效应”显著,均随输入正弦波频率、幅值的增加而增大;边坡土体峰值应变分布与坡体滑动破坏面较吻合;桩体锚索轴力与输入正弦波频率、幅值呈正相关,强震作用下锚索轴力增幅显著;桩后峰值土压力近似呈三角形分布,桩体嵌固段内桩土压力最大;桩体弯矩呈“b”型分布,嵌固段内桩体峰值弯矩最大,抗震设计中应注意验算其抗弯强度;桩后土压力与桩体加速度FFT谱幅值主要集中于低频段,结构动力响应主要受地震波低频段部分影响。

钢管锚锭板桩全回收基坑支护技术及模型试验研究

针对基坑工程中支护构件浪费、环境污染及高碳排放等问题,提出了一种钢管锚锭板桩全回收基坑支护技术并介绍了支护体系构成。实施了钢管锚锭板桩的大型缩尺模型试验,通过摄影测量技术(DIC和DPA)对模型板桩和管桩在开挖过程中的位移进行观测。试验结果表明:管桩的锚拉作用对结构位移具有显著限制,增加单位宽度的管桩数量可有效减小位移,管桩顶部的最大位移与开挖深度呈双曲线关系。模型地基的变形破坏形式与管桩至板桩的间距有关,随间距增加,破坏形态从管桩与板桩同时倾斜,到沿管桩位置滑裂,再到沿与板桩距离开挖深度约1.5倍的地表滑裂。开挖过程中管桩与板桩的桩顶变形基本协调一致。

装配式海岸工程混凝土结构研究与应用进展

码头和防波堤建筑物是典型的海岸工程混凝土结构。这类结构的下部结构构件多为预制,而上部结构构件多为现浇。针对3类典型装配式海岸工程混凝土结构(高桩码头、板桩码头、桩基透空式防波堤),系统介绍了其结构特点、典型节点与连接构造,总结分析了国内外有关这3类典型结构的力学性能、技术标准与工程应用的最新进展。最后,对今后装配式海岸工程混凝土结构的应用与研究前景进行了展望。

航道开挖对护岸结构影响的离心模型试验研究

为了研究航道开挖对新老护岸结构的影响,依托东宗线航道四改三工程,利用大型土工离心模型试验平台研究航道开挖对老挡墙护岸结构、新施工钢板桩的受力和变形特征的影响,得出航道开挖过程中板桩两侧土压力的分布规律。结果表明,随开挖深度增加,靠岸侧(主动侧)土压力逐渐减小;受板桩位移、变形及离心模型试验重液影响,临水侧(被动侧)土压力部分减小,底部土压力增大。开挖卸载导致老挡墙呈现向水侧移动且向后翻转的趋势。设计工况的极限开挖深度约为3.6 m,此时钢板桩顶部帽梁的水平位移达到0.069 m;对于6、8和10 m 3种长度的板桩,其极限开挖深度约为0.5~0.6倍桩长,且随着桩长增加极限开挖深度逐渐降低。研究得出不同板桩长度下开挖深度的阈值,可为工程建设提供技术参数。