Geotextiles and Geomembranes最新文献_第5页

Effect of backfilling surface settlement trough on waste cover leakage 回填表面沉降槽对垃圾覆盖层渗漏的影响

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-05 DOI: 10.1016/j.geotexmem.2024.09.010

Y.H. Fan, R. Kerry Rowe, Richard W.I. Brachman, Jamie F. VanGulck

The effect of backfilling of a surface differential settlement trough to reduce leakage is explored both experimentally and numerically. The field experiment examined two lined sections each with an 11 mm-diameter hole in the liner on a nominally 4 horizontal:1 vertical slope. A 2 m by 3 m, 0.3 m deep depression was filled with a 50-50 sand-snow mixture in winter to give a continuous 4H:1V slope prior to covering with the liner and 0.3 m of cover soil. Spring thaw induced a differential settlement trough up to 0.14 m deep. A second section with a similar trough was backfilled with cover soil to reinstate the 4H:1V surface while the settlement depression in the liner remained. Over the 15 months of monitoring, the backfilling reduced leakage by 57% from a annual total of 565 L to 244 L (i.e., a 60% reduction in colder seasons, from 351.3 L to 137.8 L together with a 45% reduction in warmer seasons, from 141.8 L to 77.6 L). A 3D numerical model showed encouraging agreement with the experimental results. The model indicated an inverse relationship between leakage and slope gradient, and a direct relationship between leakage and depression depth and upgradient distance to the depression. The effect of cover hydraulic conductivity was complex.

通过实验和数值计算探讨了回填表面差异沉降槽以减少渗漏的效果。现场实验检查了两个内衬区段，每个区段的内衬上都有一个直径为 11 毫米的孔，垂直坡度名义上为 4 水平:1。在一个 2 米乘 3 米、深 0.3 米的凹陷处，冬季用 50-50 的沙雪混合物填充，以形成 4H:1V 的连续斜坡，然后覆盖衬垫和 0.3 米的覆盖土。春季解冻后产生了一个深达 0.14 米的差异沉降槽。第二段类似的沉降槽用覆盖土回填，以恢复 4H:1V 的表面，而衬垫中的沉降凹陷仍然存在。在 15 个月的监测中，回填后的渗漏量减少了 57%，从每年的 565 升减少到 244 升（即在寒冷季节减少 60%，从 351.3 升减少到 137.8 升，在温暖季节减少 45%，从 141.8 升减少到 77.6 升）。三维数值模型与实验结果的一致性令人鼓舞。该模型表明，渗漏与坡度之间存在反比关系，渗漏与洼地深度和洼地上游距离之间存在直接关系。覆盖层水导率的影响很复杂。

{"title":"Effect of backfilling surface settlement trough on waste cover leakage","authors":"Y.H. Fan, R. Kerry Rowe, Richard W.I. Brachman, Jamie F. VanGulck","doi":"10.1016/j.geotexmem.2024.09.010","DOIUrl":"10.1016/j.geotexmem.2024.09.010","url":null,"abstract":"<div><div>The effect of backfilling of a surface differential settlement trough to reduce leakage is explored both experimentally and numerically. The field experiment examined two lined sections each with an 11 mm-diameter hole in the liner on a nominally 4 horizontal:1 vertical slope. A 2 m by 3 m, 0.3 m deep depression was filled with a 50-50 sand-snow mixture in winter to give a continuous 4H:1V slope prior to covering with the liner and 0.3 m of cover soil. Spring thaw induced a differential settlement trough up to 0.14 m deep. A second section with a similar trough was backfilled with cover soil to reinstate the 4H:1V surface while the settlement depression in the liner remained. Over the 15 months of monitoring, the backfilling reduced leakage by 57% from a annual total of 565 L to 244 L (i.e., a 60% reduction in colder seasons, from 351.3 L to 137.8 L together with a 45% reduction in warmer seasons, from 141.8 L to 77.6 L). A 3D numerical model showed encouraging agreement with the experimental results. The model indicated an inverse relationship between leakage and slope gradient, and a direct relationship between leakage and depression depth and upgradient distance to the depression. The effect of cover hydraulic conductivity was complex.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 277-294"},"PeriodicalIF":4.7,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modified approach for predicting seismic-induced deformation of landfills considering strength parameters of GMB-GCL interface within the liner system 考虑衬垫系统内 GMB-GCL 界面强度参数的垃圾填埋场地震诱发变形预测修正方法

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-04 DOI: 10.1016/j.geotexmem.2024.09.016

Shi-Jin Feng , Jin-Shui Ju , Qi-Teng Zheng , Xiao-Lei Zhang , Yong Zhao

This study presents an innovative methodology for predicting seismic-induced sliding displacement, a key determinant in evaluating the seismic stability of landfills. The novelty of this research lies in the incorporation of the softening characteristics of the geosynthetic interface within the liner system, a factor that has been largely overlooked in previous studies. A dynamic stability analysis was performed on a landfill using the ABAQUS software, with an emphasis on the impact of coupled parameters, particularly the strength of the interface. The results highlight PGA (Peak Ground Acceleration), PGV (Peak Ground Velocity), I_a (Arias Intensity), and residual interface shear strength (μ) as effective predictors. The study further identifies the combination of PGA and μ as the optimal parameter pairing for predicting the seismic permanent deformation of the landfill. A multi-dimensional data regression approach was employed to propose a calculation formula for seismic permanent deformation, taking into account liner damage. To enhance the seismic design methodology for landfills, the probability density function was integrated into the study. This innovative approach provides a new perspective on seismic stability assessment in landfill engineering and designs.

本研究提出了一种预测地震引起的滑动位移的创新方法，这是评估垃圾填埋场地震稳定性的一个关键决定因素。这项研究的新颖之处在于将土工合成材料界面的软化特性纳入了衬垫系统，而这一因素在以往的研究中大多被忽视。使用 ABAQUS 软件对垃圾填埋场进行了动态稳定性分析，重点关注耦合参数的影响，尤其是界面强度。结果表明，PGA（峰值地面加速度）、PGV（峰值地面速度）、Ia（阿里亚斯强度）和残余界面剪切强度 (μ) 是有效的预测参数。研究进一步确定了 PGA 和 μ 的组合是预测垃圾填埋场地震永久变形的最佳参数组合。采用多维数据回归方法，提出了地震永久变形的计算公式，并考虑了衬垫的损坏。为了加强垃圾填埋场的抗震设计方法，研究中还纳入了概率密度函数。这一创新方法为垃圾填埋场工程和设计中的地震稳定性评估提供了新的视角。

{"title":"Modified approach for predicting seismic-induced deformation of landfills considering strength parameters of GMB-GCL interface within the liner system","authors":"Shi-Jin Feng , Jin-Shui Ju , Qi-Teng Zheng , Xiao-Lei Zhang , Yong Zhao","doi":"10.1016/j.geotexmem.2024.09.016","DOIUrl":"10.1016/j.geotexmem.2024.09.016","url":null,"abstract":"<div><div>This study presents an innovative methodology for predicting seismic-induced sliding displacement, a key determinant in evaluating the seismic stability of landfills. The novelty of this research lies in the incorporation of the softening characteristics of the geosynthetic interface within the liner system, a factor that has been largely overlooked in previous studies. A dynamic stability analysis was performed on a landfill using the ABAQUS software, with an emphasis on the impact of coupled parameters, particularly the strength of the interface. The results highlight PGA (Peak Ground Acceleration), PGV (Peak Ground Velocity), I<sub>a</sub> (Arias Intensity), and residual interface shear strength (μ) as effective predictors. The study further identifies the combination of PGA and μ as the optimal parameter pairing for predicting the seismic permanent deformation of the landfill. A multi-dimensional data regression approach was employed to propose a calculation formula for seismic permanent deformation, taking into account liner damage. To enhance the seismic design methodology for landfills, the probability density function was integrated into the study. This innovative approach provides a new perspective on seismic stability assessment in landfill engineering and designs.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 247-259"},"PeriodicalIF":4.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Performance of unreinforced and geogrid-reinforced pile-supported embankments under localized surface loading: Analytical investigation 局部地表荷载下无加固和土工格栅加固桩支撑路堤的性能：分析研究

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-04 DOI: 10.1016/j.geotexmem.2024.09.017

Geye Li , Chao Xu , Chungsik Yoo , Panpan Shen , Qingming Wang

An analytical solution is proposed to identify the performance of unreinforced and geogrid-reinforcement pile-supported embankments under localized surface loading at working stress conditions based on the total efficacy and efficacy induced by soil arching alone, average strain of geogrid reinforcement, and average settlement of subsoil. This solution considered interactively soil arching within the embankment fill, the load-deflection behavior of geogrid reinforcement (if existed), and subsoil settlement. Specifically, the soil arching consisted of a structural arch with different stress states (evaluated by the elastoplastic state coefficient K) and a frictional arch. The load-deflection behavior of geogrid reinforcement was modeled by a membrane, with due consideration of the skin friction between the geogrid and soil. The subsoil was idealized as a one-dimensional compression model. The effectiveness of the proposed solution was verified by comparisons with results from the collected literature. It is shown that geogrid reinforcement improved the performance of embankments with low subsoil stiffness significantly more than that of those with high stiffness subsoil. A high tensile stiffness geogrid was found to be inefficient because its contribution to reducing the subsoil settlement and enhancing the load transfer efficacy was minimal. This paper provides a significant reference for optimizing these embankment design.

本文提出了一种分析解决方案，以确定无加固和土工格栅加固桩支撑路堤在工作应力条件下承受局部地表荷载时的性能，其依据是土拱引起的总功效和单独功效、土工格栅加固的平均应变以及基土的平均沉降。该方案综合考虑了路堤填土中的土拱效应、土工格栅加固（如存在）的荷载-挠度行为以及底土沉降。具体来说，土拱包括具有不同应力状态（通过弹塑性状态系数 K 评估）的结构拱和摩擦拱。土工格栅加固的荷载-挠度行为是通过膜来模拟的，并适当考虑了土工格栅与土壤之间的表皮摩擦。底土被理想化为一维压缩模型。通过与收集到的文献结果进行比较，验证了所提解决方案的有效性。结果表明，土工格栅加固对低基土刚度路堤性能的改善程度明显高于高基土刚度路堤。研究发现，高拉伸刚度土工格栅的效率很低，因为它对减少基土沉降和提高荷载传递效率的作用微乎其微。本文为优化这些路堤设计提供了重要参考。

{"title":"Performance of unreinforced and geogrid-reinforced pile-supported embankments under localized surface loading: Analytical investigation","authors":"Geye Li , Chao Xu , Chungsik Yoo , Panpan Shen , Qingming Wang","doi":"10.1016/j.geotexmem.2024.09.017","DOIUrl":"10.1016/j.geotexmem.2024.09.017","url":null,"abstract":"<div><div>An analytical solution is proposed to identify the performance of unreinforced and geogrid-reinforcement pile-supported embankments under localized surface loading at working stress conditions based on the total efficacy and efficacy induced by soil arching alone, average strain of geogrid reinforcement, and average settlement of subsoil. This solution considered interactively soil arching within the embankment fill, the load-deflection behavior of geogrid reinforcement (if existed), and subsoil settlement. Specifically, the soil arching consisted of a structural arch with different stress states (evaluated by the elastoplastic state coefficient <em>K</em>) and a frictional arch. The load-deflection behavior of geogrid reinforcement was modeled by a membrane, with due consideration of the skin friction between the geogrid and soil. The subsoil was idealized as a one-dimensional compression model. The effectiveness of the proposed solution was verified by comparisons with results from the collected literature. It is shown that geogrid reinforcement improved the performance of embankments with low subsoil stiffness significantly more than that of those with high stiffness subsoil. A high tensile stiffness geogrid was found to be inefficient because its contribution to reducing the subsoil settlement and enhancing the load transfer efficacy was minimal. This paper provides a significant reference for optimizing these embankment design.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 260-276"},"PeriodicalIF":4.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A 9-year study of the degradation of a HDPE geomembrane liner used in different high pH mining applications 对高密度聚乙烯（HDPE）土工膜衬垫在不同高 pH 值采矿应用中的降解情况进行为期 9 年的研究

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-02 DOI: 10.1016/j.geotexmem.2024.09.012

Rodrigo A. e Silva , Fady B. Abdelaal , R. Kerry Rowe

The degradation of a HDPE geomembrane in heap leaching environments is evaluated using immersion tests at five temperatures. The incubation solutions had a pH of 9.5, 11.5, and 13.5, relevant to gold and silver pregnant liquor solutions. After 9.3 years, the geomembrane's mechanical properties had reached nominal failure at 95, 85, and 75 °C in all three solutions. It is shown that the pH 13.5 solution had the greatest effect on the antioxidant depletion (Stage I) and polymer degradation (Stage III), but was the least aggressive to initiate the degradation (Stage II) compared to the pH 11.5 and 9.5 solutions. Overall, the time to nominal failure (time to 50% of the initial or specified property value) in pH 13.5 was slightly shorter than the pH 9.5 and 11.5 solutions. Based purely on immsersion tests, the time to nominal failure of this specific geeomembrane at 30^oC is predicted to be 150 years in the pH 9.5 and 11.5 solutions, and 140 years in the pH 13.5 solution. Assuming a good liner design that limits the tensile strains in the GMB, nominal failure in a composite liner configuration is predicted to exceed 260 years at 30 °C and the expected value could exceed 1000 years at 10 °C.

通过在五种温度下进行浸泡试验，评估了高密度聚乙烯（HDPE）土工膜在堆浸环境中的降解情况。培养液的 pH 值分别为 9.5、11.5 和 13.5，与金和银的孕液溶液相关。9.3 年后，在所有三种溶液中，土工膜的机械性能在 95、85 和 75 °C 下均达到额定失效值。结果表明，与 pH 值为 11.5 和 9.5 的溶液相比，pH 值为 13.5 的溶液对抗氧化剂消耗（第一阶段）和聚合物降解（第三阶段）的影响最大，但对启动降解（第二阶段）的作用最小。总体而言，pH 值为 13.5 的溶液的标称失效时间（达到初始值或指定性能值 50%的时间）略短于 pH 值为 9.5 和 11.5 的溶液。纯粹根据浸入试验，在 30 摄氏度的条件下，pH 值为 9.5 和 11.5 的溶液中，这种特定的吉奥膜的标称失效时间预计为 150 年，pH 值为 13.5 的溶液中为 140 年。假定有一个良好的内衬设计来限制 GMB 中的拉伸应变，在 30 °C 时，复合内衬配置的名义失效时间预计将超过 260 年，在 10 °C 时，预期值可能超过 1000 年。

{"title":"A 9-year study of the degradation of a HDPE geomembrane liner used in different high pH mining applications","authors":"Rodrigo A. e Silva , Fady B. Abdelaal , R. Kerry Rowe","doi":"10.1016/j.geotexmem.2024.09.012","DOIUrl":"10.1016/j.geotexmem.2024.09.012","url":null,"abstract":"<div><div>The degradation of a HDPE geomembrane in heap leaching environments is evaluated using immersion tests at five temperatures. The incubation solutions had a pH of 9.5, 11.5, and 13.5, relevant to gold and silver pregnant liquor solutions. After 9.3 years, the geomembrane's mechanical properties had reached nominal failure at 95, 85, and 75 °C in all three solutions. It is shown that the pH 13.5 solution had the greatest effect on the antioxidant depletion (Stage I) and polymer degradation (Stage III), but was the least aggressive to initiate the degradation (Stage II) compared to the pH 11.5 and 9.5 solutions. Overall, the time to nominal failure (time to 50% of the initial or specified property value) in pH 13.5 was slightly shorter than the pH 9.5 and 11.5 solutions. Based purely on immsersion tests, the time to nominal failure of this specific geeomembrane at 30<sup>o</sup>C is predicted to be 150 years in the pH 9.5 and 11.5 solutions, and 140 years in the pH 13.5 solution. Assuming a good liner design that limits the tensile strains in the GMB, nominal failure in a composite liner configuration is predicted to exceed 260 years at 30 °C and the expected value could exceed 1000 years at 10 °C.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 230-246"},"PeriodicalIF":4.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

DEM investigation on mechanical behavior of geogrid-sand interface subjected to cyclic direct shear 土工格栅-砂界面在循环直接剪切作用下的力学行为 DEM 研究

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-01 DOI: 10.1016/j.geotexmem.2024.09.014

Qiang Ma , Chuchen Xi , Chenxi Miao , Yongli Liu , Feng Wu

The cyclic properties of geosynthetic soil interface are crucial for reinforced soil structures subject to seismic loading. To investigate the mechanical geogrid-sand interface behavior under cyclic shear conditions, a series of numerical simulation cyclic shear tests were conducted using the discrete element method. The results revealed with increasing of shear cycles, dense sand sample gradually shrunk, exhibiting obvious softening characteristics. The vertical displacement of the sample under simulated 10 cyclic shear increases by 0.27 mm, which is 0.41 mm lower than that under 1 cyclic shear. Meanwhile, obvious dilation was observed in the shear band. As the number of cyclic shear increases, the region where the particle rotation occurs does not change significantly, ranging from 75 mm to 125 mm. Higher sample density made it more difficult for particles at geogrid-sand interface to rotate. Under the same number of cycles, denser samples had narrower shear bands, smaller shear strain shifts, and larger shear stiffness. The sand size is 0.5 mm, and the particle displacement concentrated in the 3 mm shear zone. After the completion of cyclic shear, dense sand had little effect on the porosity of the unreinforced sand affected zone, and the porosity after cyclic cycle was close to the initial porosity.

土工合成材料土壤界面的循环特性对于承受地震荷载的加筋土结构至关重要。为研究土工格栅-砂土界面在循环剪切条件下的力学行为，采用离散元法进行了一系列数值模拟循环剪切试验。结果表明，随着剪切循环次数的增加，致密砂样逐渐收缩，表现出明显的软化特征。在模拟 10 次循环剪切作用下，试样的垂直位移增加了 0.27 毫米，比 1 次循环剪切作用下的垂直位移减少了 0.41 毫米。同时，剪切带出现了明显的扩张。随着循环剪切次数的增加，颗粒发生旋转的区域变化不大，从 75 毫米到 125 毫米不等。样品密度越高，土工格栅-砂界面上的颗粒越难旋转。在相同的循环次数下，密度大的样品剪切带更窄、剪切应变位移更小、剪切刚度更大。砂的粒径为 0.5 毫米，颗粒位移集中在 3 毫米的剪切区。循环剪切完成后，致密砂对未加固砂影响区的孔隙率影响不大，循环周期后的孔隙率接近初始孔隙率。

{"title":"DEM investigation on mechanical behavior of geogrid-sand interface subjected to cyclic direct shear","authors":"Qiang Ma , Chuchen Xi , Chenxi Miao , Yongli Liu , Feng Wu","doi":"10.1016/j.geotexmem.2024.09.014","DOIUrl":"10.1016/j.geotexmem.2024.09.014","url":null,"abstract":"<div><div>The cyclic properties of geosynthetic soil interface are crucial for reinforced soil structures subject to seismic loading. To investigate the mechanical geogrid-sand interface behavior under cyclic shear conditions, a series of numerical simulation cyclic shear tests were conducted using the discrete element method. The results revealed with increasing of shear cycles, dense sand sample gradually shrunk, exhibiting obvious softening characteristics. The vertical displacement of the sample under simulated 10 cyclic shear increases by 0.27 mm, which is 0.41 mm lower than that under 1 cyclic shear. Meanwhile, obvious dilation was observed in the shear band. As the number of cyclic shear increases, the region where the particle rotation occurs does not change significantly, ranging from 75 mm to 125 mm. Higher sample density made it more difficult for particles at geogrid-sand interface to rotate. Under the same number of cycles, denser samples had narrower shear bands, smaller shear strain shifts, and larger shear stiffness. The sand size is 0.5 mm, and the particle displacement concentrated in the 3 mm shear zone. After the completion of cyclic shear, dense sand had little effect on the porosity of the unreinforced sand affected zone, and the porosity after cyclic cycle was close to the initial porosity.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 217-229"},"PeriodicalIF":4.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental study on deformation and failure mechanism of geogrid-reinforced soil above voids 空隙上方土工格栅加固土体的变形和破坏机理试验研究

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-09-28 DOI: 10.1016/j.geotexmem.2024.09.015

Yu-Xin Gao , Hong-Hu Zhu , Jing-Wen Su , Xu-Yan Ren , Xu-Hui Guo , Hannah Wan-Huan Zhou , Bin Shi

Geosynthetic materials are crucial for reinforcing soil above subterranean voids. However, the complexities of load transfer mechanisms in reinforced structures remain elusive. This study investigates the deformation and failure mechanisms in geogrid-reinforced soil using trapdoor experiments. The particle image velocimetry (PIV) technique was utilized for detailed observation of soil deformation, while fiber optic strain sensing cables were used to monitor tensile strains within geogrids. Results indicate that soil arching redistributes loads across the trapdoor area, effectively transferring loads from subsiding to adjacent stable regions. As trapdoor displacement increases, the initial soil arch collapses, prompting the formation of another stable arch. This cycle of development and failure of soil arch continues until shear bands reach the ground surface. Soil arches are more prone to failure over shallower voids. Strain data reveal that the geogrid's tension varies with the tensile strain and is highest near the void's edges. For shallow voids, the tensioned membrane effect of the geogrid bears more of the overlying soil weight, whereas for deeper voids, soil arching plays a more significant role in load transfer. This study provides important insights into the interaction between soil arching and tensioned membrane effects, offering potential implications for optimizing geosynthetic design.

土工合成材料对于加固地下空隙上的土壤至关重要。然而，加固结构中荷载传递机制的复杂性仍然难以捉摸。本研究利用活门实验研究了土工格栅加固土壤的变形和破坏机制。利用粒子图像测速仪（PIV）技术对土壤变形进行了详细观测，同时使用光纤应变传感电缆监测土工格栅内的拉伸应变。结果表明，土壤拱起重新分配了整个活门区域的荷载，有效地将荷载从下沉区域转移到邻近的稳定区域。随着活门位移的增加，最初的土拱坍塌，促使另一个稳定的土拱形成。土拱的形成和破坏循环往复，直到剪切带到达地表。土拱在较浅的空隙处更容易破坏。应变数据显示，土工格栅的拉力随拉伸应变而变化，在空隙边缘附近拉力最大。对于较浅的空隙，土工格栅的拉伸膜效应承担了更多的上覆土壤重量，而对于较深的空隙，土壤拱起在荷载传递中起着更重要的作用。这项研究为了解土壤拱起和拉伸膜效应之间的相互作用提供了重要的见解，为优化土工合成材料的设计提供了潜在的影响。

{"title":"Experimental study on deformation and failure mechanism of geogrid-reinforced soil above voids","authors":"Yu-Xin Gao , Hong-Hu Zhu , Jing-Wen Su , Xu-Yan Ren , Xu-Hui Guo , Hannah Wan-Huan Zhou , Bin Shi","doi":"10.1016/j.geotexmem.2024.09.015","DOIUrl":"10.1016/j.geotexmem.2024.09.015","url":null,"abstract":"<div><div>Geosynthetic materials are crucial for reinforcing soil above subterranean voids. However, the complexities of load transfer mechanisms in reinforced structures remain elusive. This study investigates the deformation and failure mechanisms in geogrid-reinforced soil using trapdoor experiments. The particle image velocimetry (PIV) technique was utilized for detailed observation of soil deformation, while fiber optic strain sensing cables were used to monitor tensile strains within geogrids. Results indicate that soil arching redistributes loads across the trapdoor area, effectively transferring loads from subsiding to adjacent stable regions. As trapdoor displacement increases, the initial soil arch collapses, prompting the formation of another stable arch. This cycle of development and failure of soil arch continues until shear bands reach the ground surface. Soil arches are more prone to failure over shallower voids. Strain data reveal that the geogrid's tension varies with the tensile strain and is highest near the void's edges. For shallow voids, the tensioned membrane effect of the geogrid bears more of the overlying soil weight, whereas for deeper voids, soil arching plays a more significant role in load transfer. This study provides important insights into the interaction between soil arching and tensioned membrane effects, offering potential implications for optimizing geosynthetic design.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 203-216"},"PeriodicalIF":4.7,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-scale behaviour of sand-geosynthetic interactions considering particle size effects 考虑到粒径效应的砂土合成相互作用的多尺度行为

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-09-26 DOI: 10.1016/j.geotexmem.2024.09.008

Rizwan Khan, Gali Madhavi Latha

The continuous evolution of digital imaging and sensing technologies helps in understanding the multi-scale interactions between soils and geosynthetic inclusions in a progressively better way. In this study, advanced techniques like X-ray micro-computed tomography (μCT) and profilometry are used to provide better understanding of the multi-scale interactions between sand and geosynthetic materials in direct shear interface tests. To cover the dilative and non-dilative interfaces and sands of different particle sizes, shear tests were carried out with a woven geotextile and a smooth geomembrane interfacing with three graded sands at different normal stresses. The shear response of different interfaces is analyzed in the light of 3D multi-scale morphology of particles and the roughness of tested geosynthetic surfaces to compare the peak and residual friction angles and shear zone thickness determined using Digital Image Correlation (DIC) technique. The average peak frictional efficiencies for sand-geotextile and sand-geomembrane interfaces are 0.84 and 0.52, respectively. The extent of the shear zone increased with the increase in particle size, with its average thickness ranging from 2.22 to 11.41 times the mean particle size. On a microscopic level, fine sands cause increased shear-induced changes on geomembrane surfaces because of their greater effective contact per unit area.

数字成像和传感技术的不断发展有助于更好地理解土壤与土工合成材料之间的多尺度相互作用。在这项研究中，X 射线微型计算机断层扫描（μCT）和轮廓测量等先进技术被用来更好地理解砂和土工合成材料在直接剪切界面试验中的多尺度相互作用。为了涵盖扩张性和非扩张性界面以及不同粒径的砂，在不同法向应力下，对编织土工织物和光滑土工膜与三种分级砂的界面进行了剪切试验。根据颗粒的三维多尺度形态和测试土工合成材料表面的粗糙度分析了不同界面的剪切响应，比较了峰值摩擦角和残余摩擦角以及使用数字图像相关（DIC）技术测定的剪切区厚度。砂-土工织物和砂-土工膜界面的平均峰值摩擦效率分别为 0.84 和 0.52。剪切区的范围随着粒径的增加而增大，其平均厚度为平均粒径的 2.22 至 11.41 倍。在微观层面上，细砂由于单位面积上的有效接触面积更大，因此在土工膜表面引起的剪切变化也更大。

{"title":"Multi-scale behaviour of sand-geosynthetic interactions considering particle size effects","authors":"Rizwan Khan, Gali Madhavi Latha","doi":"10.1016/j.geotexmem.2024.09.008","DOIUrl":"10.1016/j.geotexmem.2024.09.008","url":null,"abstract":"<div><div>The continuous evolution of digital imaging and sensing technologies helps in understanding the multi-scale interactions between soils and geosynthetic inclusions in a progressively better way. In this study, advanced techniques like X-ray micro-computed tomography (μCT) and profilometry are used to provide better understanding of the multi-scale interactions between sand and geosynthetic materials in direct shear interface tests. To cover the dilative and non-dilative interfaces and sands of different particle sizes, shear tests were carried out with a woven geotextile and a smooth geomembrane interfacing with three graded sands at different normal stresses. The shear response of different interfaces is analyzed in the light of 3D multi-scale morphology of particles and the roughness of tested geosynthetic surfaces to compare the peak and residual friction angles and shear zone thickness determined using Digital Image Correlation (DIC) technique. The average peak frictional efficiencies for sand-geotextile and sand-geomembrane interfaces are 0.84 and 0.52, respectively. The extent of the shear zone increased with the increase in particle size, with its average thickness ranging from 2.22 to 11.41 times the mean particle size. On a microscopic level, fine sands cause increased shear-induced changes on geomembrane surfaces because of their greater effective contact per unit area.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 169-187"},"PeriodicalIF":4.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biological clogging of geotextiles under discontinuous fermentation scenario 非连续发酵情况下土工织物的生物堵塞问题

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-09-26 DOI: 10.1016/j.geotexmem.2024.09.013

Julieta de Goycoechea , Marcos A. Montoro , Daniel A. Glatstein , Karina F. Crespo Andrada , María Gabriela Paraje

This article presents the effect of biological clogging on the hydraulic performance of geotextiles used for the construction of filter and drainage in landfills. Clogging tests were performed on specimens of woven and non-woven geotextiles in a discontinuous fermentation scenario using natural leachate and a nutrient solution. The consequences of biological clogging were assessed through experimental measurements of changes in the cross-plane hydraulic conductivity and the impregnation ratio of different geotextiles specimens at different immersion times. Porosity reduction was then back-calculated from the hydraulic conductivity results using the Kozeny-Carman equation. Additionally, the impact of an antibiotic and antifungal solution on biofilm development was evaluated. It was demonstrated that the cross-plane hydraulic conductivity of geotextile specimens decreases as biomass accumulation per unit area increases with immersion time. The application of an antibiotic and antifungal solution resulted in a porosity recovery of over 90% and a hydraulic conductivity recovery ranging from 78 to 83% for both woven and non-woven geotextiles. These results demonstrate that the clogging was primarily due to biological activity. Despite certain limitations in measurement and definition, the impregnation ratio proved to be a reliable parameter for the evaluation of biological clogging.

本文介绍了生物堵塞对用于垃圾填埋场过滤和排水工程的土工织物水力性能的影响。在使用天然渗滤液和营养液进行不连续发酵的情况下，对有纺和无纺土工织物试样进行了堵塞测试。通过实验测量不同土工织物试样在不同浸泡时间下的横面水导率和浸渍率的变化，评估了生物堵塞的后果。然后利用 Kozeny-Carman 方程根据水力传导结果反向计算孔隙率的降低。此外，还评估了抗生素和抗真菌溶液对生物膜发展的影响。结果表明，随着浸泡时间的延长，单位面积上的生物量积累越多，土工织物试样的横面水力传导率就越低。使用抗生素和抗真菌溶液后，编织土工织物和无纺土工织物的孔隙率恢复了 90% 以上，水导率恢复了 78% 至 83%。这些结果表明，堵塞主要是由于生物活性造成的。尽管在测量和定义方面存在一定的局限性，但事实证明浸渍率是评估生物堵塞的一个可靠参数。

{"title":"Biological clogging of geotextiles under discontinuous fermentation scenario","authors":"Julieta de Goycoechea , Marcos A. Montoro , Daniel A. Glatstein , Karina F. Crespo Andrada , María Gabriela Paraje","doi":"10.1016/j.geotexmem.2024.09.013","DOIUrl":"10.1016/j.geotexmem.2024.09.013","url":null,"abstract":"<div><div>This article presents the effect of biological clogging on the hydraulic performance of geotextiles used for the construction of filter and drainage in landfills. Clogging tests were performed on specimens of woven and non-woven geotextiles in a discontinuous fermentation scenario using natural leachate and a nutrient solution. The consequences of biological clogging were assessed through experimental measurements of changes in the cross-plane hydraulic conductivity and the impregnation ratio of different geotextiles specimens at different immersion times. Porosity reduction was then back-calculated from the hydraulic conductivity results using the Kozeny-Carman equation. Additionally, the impact of an antibiotic and antifungal solution on biofilm development was evaluated. It was demonstrated that the cross-plane hydraulic conductivity of geotextile specimens decreases as biomass accumulation per unit area increases with immersion time. The application of an antibiotic and antifungal solution resulted in a porosity recovery of over 90% and a hydraulic conductivity recovery ranging from 78 to 83% for both woven and non-woven geotextiles. These results demonstrate that the clogging was primarily due to biological activity. Despite certain limitations in measurement and definition, the impregnation ratio proved to be a reliable parameter for the evaluation of biological clogging.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 188-202"},"PeriodicalIF":4.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New theoretical solution for soft soil consolidation under vacuum pressure via horizontal drainage enhanced geotextile sheets 通过水平排水增强土工织物片材实现真空压力下软土固结的新理论解决方案

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-09-25 DOI: 10.1016/j.geotexmem.2024.09.011

Hao Chen , Jian Chu , Shifan Wu , Wei Guo , Kokpang Lam

Land reclamation is a major construction activity in Singapore and other Asian countries. When granular fills become scarce, soft materials have to be used for land reclamation. A new land reclamation and soil improvement method using vacuum preloading and horizontal drainage enhanced non-woven geotextile (HDeG) sheets for soft soil consolidation has been proposed to reduce consolidation time and save costs. This paper presents a new theoretical solution for analysing the consolidation process of soil under vacuum pressure via horizontal drainage enhanced geotextile sheets as such a solution is not available yet. To verify the proposed theoretical solution, model tests and finite element analyses (FEA) have also been conducted. The proposed analytical solution agrees well with the results from FEA and the model tests in settlement, average effective stress and degree of consolidation. Thus, this solution could be used for design and analysis for land reclamation with soft materials consolidated using vacuum preloading together with HDeG sheets or other horizontal drainage materials with an adequately high transmissivity. The prediction of the consolidation performance relies on the proper selection of the coefficient of consolidation based on the effective stress history of soil.

在新加坡和其他亚洲国家，填海造地是一项主要的建筑活动。当粒状填料变得稀缺时，就必须使用软质材料进行土地开垦。有人提出了一种新的土地开垦和土壤改良方法，利用真空预加载和水平排水增强型无纺土工织物（HDeG）片材进行软土固结，以缩短固结时间并节约成本。本文提出了一种新的理论解决方案，用于分析真空压力下通过水平排水增强土工织物片材进行土壤固结的过程，因为目前还没有这种解决方案。为了验证所提出的理论解决方案，还进行了模型试验和有限元分析（FEA）。在沉降、平均有效应力和固结程度方面，所提出的分析解决方案与有限元分析和模型试验的结果非常吻合。因此，该方案可用于设计和分析使用真空预加载技术加固的软质材料以及高密度聚乙烯板材或其他具有足够高渗透率的水平排水材料的土地开垦。固结性能的预测依赖于根据土壤的有效应力历史正确选择固结系数。

{"title":"New theoretical solution for soft soil consolidation under vacuum pressure via horizontal drainage enhanced geotextile sheets","authors":"Hao Chen , Jian Chu , Shifan Wu , Wei Guo , Kokpang Lam","doi":"10.1016/j.geotexmem.2024.09.011","DOIUrl":"10.1016/j.geotexmem.2024.09.011","url":null,"abstract":"<div><div>Land reclamation is a major construction activity in Singapore and other Asian countries. When granular fills become scarce, soft materials have to be used for land reclamation. A new land reclamation and soil improvement method using vacuum preloading and horizontal drainage enhanced non-woven geotextile (HDeG) sheets for soft soil consolidation has been proposed to reduce consolidation time and save costs. This paper presents a new theoretical solution for analysing the consolidation process of soil under vacuum pressure via horizontal drainage enhanced geotextile sheets as such a solution is not available yet. To verify the proposed theoretical solution, model tests and finite element analyses (FEA) have also been conducted. The proposed analytical solution agrees well with the results from FEA and the model tests in settlement, average effective stress and degree of consolidation. Thus, this solution could be used for design and analysis for land reclamation with soft materials consolidated using vacuum preloading together with HDeG sheets or other horizontal drainage materials with an adequately high transmissivity. The prediction of the consolidation performance relies on the proper selection of the coefficient of consolidation based on the effective stress history of soil.</div></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 155-168"},"PeriodicalIF":4.7,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Implications of single and double liners on the impact of PFOA in landfills on an underlying aquifer 单层和双层衬垫对垃圾填埋场中全氟辛烷磺酸对地下含水层影响的影响

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-09-20 DOI: 10.1016/j.geotexmem.2024.09.009

Farah B. Barakat , R. Kerry Rowe

The transport of perfluorooctanoic acid (PFOA) through the base of a municipal solid waste landfill lined by a single or double composite liner system underlain by an aquifer is examined. Experiments conducted to obtain permeation coefficients for PFOA (and other PFAS) through HDPE and a GCL at different stress levels are described and the results presented. Experimentally derived interface transmissivity and GCL hydraulic conductivity permeated by a PFAS solution are presented. The experimentally derived parameters for PFOA are then used together with finite element software to model diffusive and diffusive-advective transport of PFOA through holed wrinkles from a landfill. The peak concentrations of PFOA in the modelled aquifer are reported and compared to the maximum allowable drinking water regulations for PFOA in different jurisdictions. A sensitivity analysis is performed to assess the effect of different parameters on the degree of contamination of the aquifer. With no holes in the geomembrane (pure diffusive transport), all regulatory limits are met for both single and double-lined barrier systems. The amount of leakage through holed wrinkles required for PFOA to exceed regulatory limits varies depending on the initial concentration of PFOA and jurisdictional allowable limits. Most results showed that the single composite liner barrier system examined is unlikely to be sufficient to contain PFOA to an acceptable level. The double liner system is more likely to meet regulatory requirements if most of the leakage through the primary is collected.

研究了全氟辛酸（PFOA）在含水层下通过单层或双层复合衬垫系统衬垫的城市固体废物填埋场底部的迁移情况。介绍了为获得 PFOA（和其他 PFAS）在不同应力水平下通过高密度聚乙烯和 GCL 的渗透系数而进行的实验，并给出了实验结果。介绍了实验得出的 PFAS 溶液渗透界面渗透率和 GCL 水导率。然后将实验得出的 PFOA 参数与有限元软件一起用于模拟 PFOA 通过垃圾填埋场孔状皱纹的扩散和扩散-平流传输。报告了建模含水层中全氟辛烷磺酸的峰值浓度，并将其与不同辖区的全氟辛烷磺酸最高允许饮用水规定进行了比较。进行了敏感性分析，以评估不同参数对含水层污染程度的影响。在土工膜无孔的情况下（纯扩散传输），单层和双层阻隔系统均符合所有法规限值。PFOA 通过有孔皱褶的渗漏量超过监管限值的情况各不相同，这取决于 PFOA 的初始浓度和辖区允许的限值。大多数结果表明，所研究的单层复合衬垫阻隔系统不太可能将 PFOA 控制在可接受的水平。如果通过主衬垫收集到大部分泄漏物，双衬垫系统更有可能满足监管要求。

{"title":"Implications of single and double liners on the impact of PFOA in landfills on an underlying aquifer","authors":"Farah B. Barakat , R. Kerry Rowe","doi":"10.1016/j.geotexmem.2024.09.009","DOIUrl":"10.1016/j.geotexmem.2024.09.009","url":null,"abstract":"<div><p>The transport of perfluorooctanoic acid (PFOA) through the base of a municipal solid waste landfill lined by a single or double composite liner system underlain by an aquifer is examined. Experiments conducted to obtain permeation coefficients for PFOA (and other PFAS) through HDPE and a GCL at different stress levels are described and the results presented. Experimentally derived interface transmissivity and GCL hydraulic conductivity permeated by a PFAS solution are presented. The experimentally derived parameters for PFOA are then used together with finite element software to model diffusive and diffusive-advective transport of PFOA through holed wrinkles from a landfill. The peak concentrations of PFOA in the modelled aquifer are reported and compared to the maximum allowable drinking water regulations for PFOA in different jurisdictions. A sensitivity analysis is performed to assess the effect of different parameters on the degree of contamination of the aquifer. With no holes in the geomembrane (pure diffusive transport), all regulatory limits are met for both single and double-lined barrier systems. The amount of leakage through holed wrinkles required for PFOA to exceed regulatory limits varies depending on the initial concentration of PFOA and jurisdictional allowable limits. Most results showed that the single composite liner barrier system examined is unlikely to be sufficient to contain PFOA to an acceptable level. The double liner system is more likely to meet regulatory requirements if most of the leakage through the primary is collected.</p></div>","PeriodicalId":55096,"journal":{"name":"Geotextiles and Geomembranes","volume":"53 1","pages":"Pages 140-154"},"PeriodicalIF":4.7,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0266114424001109/pdfft?md5=d470727bc23b223253de6962c115d4a9&pid=1-s2.0-S0266114424001109-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0