Geotextiles and Geomembranes最新文献_第4页

Bearing capacity of strip footings in unsaturated soils reinforced with layered geogrid sheets using upper bound method 用上界法计算用分层土工格栅片加固的非饱和土中条形基脚的承载力

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-11-21 DOI: 10.1016/j.geotexmem.2024.11.006

Sheng Xu, Zhen-Yu Yin

A frequently overlooked aspect in previous research on bearing capacity of reinforced foundations is the prevalent unsaturated properties of soils. This paper provides an analytical framework for evaluating the bearing capacity of strip footings with single-layer and double-layer reinforcement in unsaturated soils. Four classical nonlinear expressions are used to determine the additional cohesion induced by matric suction. Solutions for the reinforcement layer undergoing tensile failure and sliding failure are provided separately. In the former case, where the bearing capacity depends on the reinforcement's tensile strength, the Prandtl mechanism is employed. In the latter case, where the bearing capacity is influenced by the characteristics of the reinforcement-soil interface, a multi-block mechanism is adopted. Additionally, sliding failure exhibits different mechanisms depending on the reinforcement's embedded depth. By comparing the results of different failure mechanisms, accurate upper bound solutions for bearing capacity are obtained. In the case of sliding failure, the optimal reinforcement depths that maximize the bearing capacity are identified for both single-layer and double-layer reinforcement. To facilitate engineering use, the optimum depths and corresponding bearing capacity factors are given in tabular form. The effectiveness of the framework is demonstrated through comparisons with previous theories, experiments, and finite element simulation results.

在以往对加固地基承载力的研究中，一个经常被忽视的方面是土壤普遍存在的非饱和特性。本文提供了一个分析框架，用于评估非饱和土壤中单层和双层加固条形基脚的承载力。四个经典的非线性表达式用于确定母吸力引起的附加内聚力。分别提供了钢筋层拉伸破坏和滑动破坏的解决方案。在前一种情况下，承载力取决于钢筋的抗拉强度，采用的是普朗特机制。在后一种情况下，承载能力受钢筋-土壤界面特性的影响，采用的是多块机理。此外，滑动破坏因钢筋嵌入深度的不同而表现出不同的机理。通过比较不同破坏机制的结果，可以获得精确的承载力上限解。在滑动破坏的情况下，确定了单层和双层加固的最佳加固深度，从而最大限度地提高了承载能力。为便于工程使用，以表格形式给出了最佳深度和相应的承载力系数。通过与以前的理论、实验和有限元模拟结果进行比较，证明了该框架的有效性。

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引用次数: 0

Prediction method for lateral displacements of geosynthetic-reinforced soil walls with segmental block facings 土工合成材料加固土墙分段块面侧向位移预测方法

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-11-20 DOI: 10.1016/j.geotexmem.2024.11.008

Fei Zhang , Yuming Zhu , Shangchuan Yang , Yufeng Gao

Predicting the performance of geosynthetic-reinforced soil walls with segmental block facings in service is a challenging task due to their complex interaction mechanisms. This paper proposes a semi-analytical method to estimate the performance of such walls by considering a prescribed reduction factor. Rough back of the wall and unreinforced zone effects can be taken into account. It also incorporates an empirical formula to consider reinforcement stiffness to accurately characterize the nonlinear interaction between geosynthetics and soil. Seven full-scale tests and three robust numerical simulations were employed to evaluate the proposed method. The results demonstrate satisfactory estimations of lateral displacement and reinforcement force location with a rational reduction factor. Additionally, the physical significance of the reduction factor is identified, and a method for its determination based on data analysis is proposed. This method eliminates the need for sophisticated numerical analyses to determine lateral displacements. Further investigation is required to explore the correlation between the reduction factor and various design parameters, aiming to establish a more generalized formula for predicting the performance of GRS segmental walls.

由于土工合成材料加固的土墙具有复杂的相互作用机制，因此预测其使用性能是一项具有挑战性的任务。本文提出了一种半分析方法，通过考虑规定的折减系数来估算此类墙体的性能。墙体背面的粗糙和未加固区域的影响都可以考虑在内。该方法还采用了一个经验公式来考虑加固刚度，以准确描述土工合成材料与土壤之间的非线性相互作用。为评估所提出的方法，我们进行了七次全尺寸试验和三次稳健的数值模拟。结果表明，通过合理的折减系数，对侧向位移和加固力位置的估算令人满意。此外，还确定了折减系数的物理意义，并提出了基于数据分析的折减系数确定方法。这种方法无需通过复杂的数值分析来确定侧向位移。还需要进一步研究，探讨折减系数与各种设计参数之间的相关性，以建立一个更通用的公式，用于预测 GRS 分段墙的性能。

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引用次数: 0

Mitigating frost heave of a soil stabilized with sisal fiber exposed to freeze-thaw cycles 减轻用剑麻纤维加固的土壤在冻融循环中的冻胀现象

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-11-20 DOI: 10.1016/j.geotexmem.2024.10.005

Fei Deng , Jianguo Lu , Xusheng Wan , Boshi Liu , Binlong Zhang , Hao Fu

To embrace sustainable and environmentally friendly practices, sisal fibers have emerged as a green and low-carbon alternative, offering a viable approach for enhancing the physical characteristics of frost-vulnerable soils. In this study, the unconfined compressive strength and freeze-thaw cycle (FTC) tests for soils stabilized with sisal fiber were conducted, and the enhancement mechanism of sisal fibers on soils in cold regions was analyzed. The results showed that as the sisal fiber content raised, the unconfined compressive strength of the soil samples initially increased and then decreased, which reached a peak at 0.9% sisal fiber content. The heat flux in the sisal fiber-reinforced soil samples exhibited a more dramatic variation than that in the soils without adding fibers during the water-ice phase transition stage. The unfrozen water hysteresis in the fiber-reinforced soil samples initially decreased and then increased as the soil temperature decreased. With an increase in the FTCs, the frost heave for sisal fiber-reinforced soil samples occurred, whereas settlement appeared in the soils without adding fibers. The cumulative deformation of sisal fiber-reinforced soil samples was lower than that of the soils without adding fibers. Additionally, the thaw settlement rate was lower than that of frost heave rate for sisal fiber-reinforced soil samples, while the reverse results were occurred for the soils without adding fibers. The addition of sisal fibers established a more robust structural integrity to the soils.

为了实现可持续发展和环境友好型实践，剑麻纤维作为一种绿色低碳的替代品应运而生，为增强易冻土壤的物理特性提供了一种可行的方法。本研究对使用剑麻纤维稳定的土壤进行了无压抗压强度和冻融循环（FTC）试验，并分析了剑麻纤维对寒冷地区土壤的增强机理。结果表明，随着剑麻纤维含量的增加，土样的无压抗压强度先上升后下降，在剑麻纤维含量为 0.9% 时达到峰值。在水冰相变阶段，剑麻纤维加固土样中的热通量比未添加纤维的土样中的热通量变化更为剧烈。随着土壤温度的降低，纤维加固土壤样品中的解冻水滞后最初会减小，然后增大。随着 FTCs 的增加，剑麻纤维加筋土样出现了冻胀，而未添加纤维的土样则出现了沉降。剑麻纤维加固土样的累积变形量低于未添加纤维的土样。此外，剑麻纤维加固土样的解冻沉降率低于冻胀率，而未添加纤维的土样则相反。添加剑麻纤维后，土壤的结构更加坚固。

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引用次数: 0

Experimental study on vacuum preloading combined with intermittent airbag pressurization for treating dredged sludge 真空预加载与间歇气囊加压相结合处理疏浚污泥的试验研究

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-11-16 DOI: 10.1016/j.geotexmem.2024.11.001

Yajun Wu , Jinjin Wu , Yitian Lu , Xudong Zhang , Chau Nguyen Xuan Quang

The PVD-vacuum preloading method combined with airbags is a new soft ground treatment technology that can provide additional consolidation pressure and reduce lateral deformation towards the improvement area caused by traditional PVD-vacuum preloading. However, continuous airbag pressurization tends to create large cavities in the soil, and the optimal timing for airbag loading is also unclear. To address the aforementioned issues, this paper proposes an intermittent airbag pressurization method, adding small-diameter airbags between adjacent PVDs and intermittently inflating the airbags. Through indoor model test, the water discharge characteristics, improvement effect, improvement mechanism, and foundation settlement characteristics under intermittent airbag pressure were studied, proving that intermittent airbag pressure can significantly reduce early soil rebound. A calculation method for the airbag expansion diameter was proposed, and its feasibility was verified through experimental results. Finally, the optimal time period for intermittent airbag loading was clarified.

结合气囊的 PVD 真空预加载法是一种新型软土地基处理技术，可提供额外的固结压力，减少传统 PVD 真空预加载法对改良区域造成的横向变形。然而，连续的气囊加压容易在土壤中产生较大的空洞，而且气囊加载的最佳时机也不明确。针对上述问题，本文提出了一种间歇式气囊加压方法，即在相邻 PVD 之间添加小直径气囊，并对气囊进行间歇式充气。通过室内模型试验，研究了间歇气囊加压下的出水特性、改善效果、改善机理和地基沉降特性，证明间歇气囊加压可显著减少早期土体回弹。提出了气囊膨胀直径的计算方法，并通过试验结果验证了其可行性。最后，明确了间歇气囊加载的最佳时间段。

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引用次数: 0

Corrigendum to “Seismic response and mitigation measures for T shape retaining wall in liquefiable site” [Geotext. Geomembranes. 53(1), (2025) 331–349] 可液化场地 T 型挡土墙的地震响应和缓解措施"[Geotext. Geomembranes.

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-11-14 DOI: 10.1016/j.geotexmem.2024.11.005

Hongmei Gao , Yongjie Zhou , Zhihua Wang , Xinlei Zhang , Zhanpeng Ji , Kai Huang

引用次数: 0

Stress-strain responses of EPS geofoam upon cyclic simple shearing: Experimental investigations and constitutive modeling EPS 土工泡沫在循环简单剪切时的应力-应变响应：实验研究和构成模型

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-31 DOI: 10.1016/j.geotexmem.2024.10.004

Weilie Zou , Yuhang Li , Zhong Han , Qi Xiang , Xiequn Wang

This paper investigates the cyclic simple shearing behaviors of Expanded Polystyrene (EPS) geofoams considering influences of the shear strain amplitude (γ_a), number of shear cycles, shear rate, vertical stress (σ_n), and EPS density (ρ_EPS). The experimental results demonstrate that the cyclic shear stress (τ)-shear strain (γ) relationships of EPS are not sensitive to the shear rate. As the γ exceeds 2%, the EPS yields and its τ-γ relationships and backbone curve become nonlinear. There are linear relationships between the elastic modulus E, elastic shear modulus G_e, and plastic shear modulus G_p. They increase linearly with an increase in the ρ_EPS. The G_e and G_p are not sensitive to the γ_a. The cyclic shear stiffness G increases while the equivalent damping ratio D of EPS decreases with an increase in the σ_n and ρ_EPS. The G decreases while the D increases nonlinearly as the γ_a increases. Empirical models were developed to describe the variations of the G_e, G_p, G, and D with σ_n, ρ_EPS, and γ_a. A modified Hardin-Drnevich model was proposed to describe the backbone curves and τ-γ loops upon cyclic simple shearing, which has achieved good agreement with the experimental measurements and the testing results from the literature.

本文研究了发泡聚苯乙烯（EPS）土工膜的循环简单剪切行为，考虑了剪切应变振幅（γa）、剪切循环次数、剪切速率、垂直应力（σn）和 EPS 密度（ρEPS）的影响。实验结果表明，EPS 的循环剪切应力（τ）-剪切应变（γ）关系对剪切速率并不敏感。当 γ 超过 2% 时，EPS 就会屈服，其 τ-γ 关系和骨干曲线会变得非线性。弹性模量 E、弹性剪切模量 Ge 和塑性剪切模量 Gp 之间存在线性关系。它们随着 ρEPS 的增加而线性增加。Ge 和 Gp 对 γa 不敏感。循环剪切刚度 G 随 σn 和 ρEPS 的增加而增加，而 EPS 的等效阻尼比 D 则随 σn 和 ρEPS 的增加而减小。随着 γa 的增大，G 会减小，而 D 会非线性增大。建立了经验模型来描述 Ge、Gp、G 和 D 随 σn、ρEPS 和 γa 的变化。提出了一个改进的 Hardin-Drnevich 模型来描述循环简单剪切时的骨架曲线和 τ-γ 循环，该模型与实验测量结果和文献测试结果具有良好的一致性。

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引用次数: 0

Seismic response and mitigation measures for T shape retaining wall in liquefiable site 可液化场地 T 型挡土墙的地震响应和缓解措施

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-31 DOI: 10.1016/j.geotexmem.2024.10.003

Gao Hongmei , Zhou Yongjie , Wang Zhihua , Zhang Xinlei , Ji Zhanpeng , Huang Kai

Focusing on a T-shape cantilever retaining wall in a liquefiable site, a series of shaking table model tests were conducted to investigate the seismic stability characteristics of the wall when using EPS composite soil isolation piles (WEP), EPS composite soil isolation walls (WEW), and backfilled natural fine sand from Nanjing (WSS). The seismic response characteristics of the model ground soil and the retaining wall for the three models were comparatively analyzed regarding the acceleration, displacement, dynamic earth pressure and excess pore water pressure ratio. Moreover, the seismic performance of anti-liquefaction measures in the liquefiable ground with EPS composite isolation structures were discussed from the view of the phase characteristics and energy consumption. The results indicate that under the same peak ground acceleration, the excess pore water pressure in the WEP and WEW models is significantly lower than that in the WSS model. Different from WSS, WEP and WEW exhibit a segmented distribution with the buried depth in acceleration amplification factors. The embedding of isolation structures in liquefiable sites can reduce the wall sliding and rotational displacements by approximately 25%–50%. In addition, the out-of-phase characteristics of dynamic earth pressure increment are evidently different among WEP, WEW and WSS. There is an approximate 180° phase difference between the dynamic earth pressure behind the wall and the inertial force in the WEP and WEW models. EPS composite soil isolation structures show good energy dissipation characteristics, and especially the isolation wall is better than isolation pile. The displacement index of WSS retaining wall is significantly larger than that of WEW and WEP, indicating that EPS composite isolation piles and wall play an important role in the mitigating damage to the retaining wall. This study can provide references for the application of isolation structures in the liquefiable ground soil regarding the seismic stability.

针对液化场地中的 T 型悬臂挡土墙，进行了一系列振动台模型试验，研究了采用 EPS 复合土隔离桩（WEP）、EPS 复合土隔离墙（WEW）和回填南京天然细砂（WSS）时挡土墙的地震稳定性特征。比较分析了三种模型的加速度、位移、动土压力和孔隙水超压比等模型地基土和挡土墙的地震响应特性。此外，还从相位特征和能耗的角度讨论了采用 EPS 复合隔震结构的液化地层抗液化措施的抗震性能。结果表明，在相同的地表加速度峰值下，WEP 和 WEW 模型的过剩孔隙水压力明显低于 WSS 模型。与 WSS 模型不同的是，WEP 和 WEW 模型的加速度放大系数随埋设深度呈分段分布。在可液化场地嵌入隔离结构可将墙体滑动和旋转位移减少约 25%-50%。此外，WEP、WEW 和 WSS 的动土压力增量的非相位特性明显不同。在 WEP 和 WEW 模型中，墙后动土压力与惯性力之间存在大约 180° 的相位差。EPS 复合土体隔震结构表现出良好的消能特性，尤其是隔震墙的消能特性优于隔震桩。WSS 挡土墙的位移指数明显大于 WEW 和 WEP 挡土墙的位移指数，说明 EPS 复合隔震桩和隔震墙在减轻挡土墙破坏方面发挥了重要作用。本研究可为可液化地基土中隔震结构的抗震稳定性应用提供参考。

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引用次数: 0

A large-size model test study on the consolidation effect of construction waste slurry under self-weight and bottom vacuum preloading 自重和底部真空预压下建筑垃圾泥浆固结效果的大尺寸模型试验研究

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-18 DOI: 10.1016/j.geotexmem.2024.10.002

Wenhao Jiang , Liangtong Zhan , Junyao Lu

Bottom vacuum preloading (BVP) is the method of applying vacuum pressure at the bottom zone of soils to generate pore-water pressure difference between the top and bottom boundaries, thereby achieving the consolidation drainage. This study conducted a large-size model test to explore the engineering feasibility of combining self-weight and BVP to treat construction waste slurry (CWS). Through the treatment of the measures of self-weight consolidation (0–26 d) and BVP with a water cover (26–78 d), the average water content of CWS declined from 255.6% to 115.9%, and the volume reduction ratio reached 0.476. However, since these two measures could properly treat only the bottom CWS, the measures of BVP with the mud cover (78–141 d) and the natural air-drying (141–434 d) were performed to further decrease the CWS water content near the upper zone. The latter two-stage measures reduced the average water content of CWS to 84.9% and increased the volume reduction ratio to 0.581. Moreover, the measurements suggested that the treated CWS largely exhibited a shear strength of 10 kPa or more. Overall, the proposed approach appeared some engineering feasibility to treat CWS, and the performed test study could act as a reference for the practical treatment of CWS.

底部真空预压（BVP）是在土壤底部区域施加真空压力，使上下边界产生孔隙水压力差，从而实现固结排水的方法。本研究通过大尺寸模型试验，探讨了自重与 BVP 结合处理建筑垃圾泥浆（CWS）的工程可行性。通过自重固结（0-26 d）和覆水 BVP（26-78 d）措施的处理，CWS 的平均含水率从 255.6% 降至 115.9%，体积减少比达到 0.476。但是，由于这两种措施只能对底部的 CWS 进行适当处理，为了进一步降低靠近上部区域的 CWS 含水量，还采取了带泥浆覆盖的 BVP（78-141 d）和自然风干（141-434 d）措施。后两个阶段的措施将 CWS 的平均含水量降至 84.9%，并将体积减少率提高到 0.581。此外，测量结果表明，经过处理的 CWS 大多具有 10 kPa 或更高的剪切强度。总体而言，所建议的方法在处理 CWS 方面具有一定的工程可行性，所进行的试验研究可为 CWS 的实际处理提供参考。

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引用次数: 0

Observations from opening of a novel geotextile tube connection in field test site 新型土工织物管连接件在现场试验中的观察结果

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-09 DOI: 10.1016/j.geotexmem.2024.10.001

Hyeong-Joo Kim , Myoung-Soo Won , Shamsher Sadiq , Tae-Woong Park , Hyeong-Soo Kim , Young-Tak Ryu , Young-Chul Park , Ji-Hwi Gwak , Tae-Eon Kim , Jeong-Ho Choi

A novel connection configuration for geotextile tubes was proposed, involving the insertion of an auxiliary tube between two main tubes, to ensure proper alignment and leveling when connecting them in a series, thus consolidating individual tubes into a unified structure while maintaining a consistent horizontal level. The novel connection was implemented at a test bed site in the Saemangeum reclaimed area, South Korea, to test exposure to the marine environment including sea waves, sun light exposure and reclamation process. This study presents the observations made upon opening the connection tube after 8 years. The observation shows that the connected geotextile tubes using the proposed auxiliary tube are suitable for use in long-term reclamation projects.

我们提出了一种土工织物管的新型连接构造，即在两根主管之间插入一根辅助管，以确保在将它们串联起来时正确对齐和找平，从而将单根管整合成一个统一的结构，同时保持一致的水平面。这种新型连接方式在韩国新万金填海区的试验场地实施，以测试暴露于海洋环境（包括海浪、日光照射和填海过程）的情况。本研究介绍了 8 年后打开连接管时的观察结果。观察结果表明，使用拟议辅助管的连接土工织物管适合在长期填海项目中使用。

引用次数: 0

Liquefaction and reliquefaction mitigation of sand specimen treated with prefabricated vertical drains: An experimental investigation 用预制垂直排水沟处理砂试样的液化和再液化缓解：实验研究

IF 4.7 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Geotextiles and Geomembranes

Pub Date : 2024-10-08 DOI: 10.1016/j.geotexmem.2024.09.018

B.K. Maheshwari , Gowtham Padmanabhan

This study examines the performance of prefabricated vertical drains (PVD) against liquefaction and reliquefaction. A series of 102 shakings were performed using 1g shaking table apparatus on untreated and treated sand specimens prepared with 25% relative density. Sinusoidal waveform experimented with three different repeated shaking patterns and independent events for two different frequencies (2 Hz and 3.5 Hz) with 1-min duration. Two different installation methods; drainage alone method (PVD-D) and drainage along with densification (PVD-DD) were experimented. Durability of PVD were examined from geotextile tensile testing apparatus and digital image correlation. These experiments demonstrated excellent durability characteristics of PVD filter even after exposed to repeated shakings. Treated specimens improved the resistance to reliquefaction due to radial drainage offered by PVD which has retarded the excess pore pressure (EPP) generation. In addition, densification induced during the installation of PVD also contributed for restricting EPP, however, the induced sand densification achieved during repeated shaking events were not responsible for increased resistance against liquefaction/reliquefaction. Results indicate that the maximum pore pressure ratio in treated specimens were restricted within threshold design limit (≤0.60) for most of the events, even when the untreated specimens completely liquefied or generated a maximum value near unity.

本研究考察了预制垂直排水沟（PVD）抗液化和再液化的性能。使用 1g 振动台仪器对未处理和已处理的相对密度为 25% 的砂试样进行了 102 次系列振动。用三种不同的重复振动模式和两种不同频率（2 Hz 和 3.5 Hz）、持续时间为 1 分钟的独立事件进行了正弦波形试验。试验了两种不同的安装方法：单独排水法（PVD-D）和排水与致密化法（PVD-DD）。通过土工织物拉伸试验设备和数字图像相关性检验了 PVD 的耐久性。这些实验表明，PVD 过滤器即使在反复震动的情况下也具有出色的耐久性能。由于 PVD 提供的径向排水功能延缓了过剩孔隙压力（EPP）的产生，经过处理的试样提高了抗再塌陷能力。此外，在安装 PVD 过程中引起的致密化也有助于限制 EPP，但是，在反复摇晃过程中引起的砂致密化并不是提高抗液化/再液化能力的原因。结果表明，即使未经处理的试样完全液化或产生接近于 1 的最大值，经过处理的试样的最大孔隙压力比在大多数事件中也被限制在阈值设计限值（≤0.60）之内。

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引用次数: 0