Transportation Geotechnics最新文献_第5页

Influence of sequential twin stacked tunnelling on deformation and load-transfer mechanisms of battered piled rafts under lateral and combined loading 序贯双桩隧道开挖对横向和组合荷载作用下破桩筏变形及荷载传递机制的影响

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-18 DOI: 10.1016/j.trgeo.2025.101852

Mukhtiar Ali Soomro , Sharafat Ali Darban , Rizwan Ali Soomro , Zhen-Dong Cui , Amir Detho , Saim Bin Shahab

The increasing demand for underground space in dense urban areas has led to the construction of twin stacked tunnels, creating complex soil-structure interactions with nearby piled foundations. This study investigates the effects of twin stacked tunnelling on the performance of a (2 × 2) battered piled raft system in soft clay using three-dimensional coupled-consolidation finite element analyses. A hypoplastic clay model was employed to capture soil stiffness degradation and stress-path-dependent behaviour, calibrated through laboratory tests and validated against centrifuge data. The first tunnel was excavated adjacent to the pile shaft, and the second tunnel at varying depths near the pile toe, below the pile toe, and beneath the raft (denoted by StackTwinST, StackTwinSB, and StackTwinSU, respectively). Additional analyses examined the effects of combined vertical-lateral loading conditions and construction sequence. Results show that the first tunnel excavation caused stress release and degradation of mobilized shear stiffness, reducing shaft resistance in the upper pile portion by up to 28 %. The second tunnelling increased deformation, particularly beneath the raft (StackTwinSU), with maximum lateral displacement of 8.6 % of pile diameter and raft tilting of 0.64 %. Under combined loading, lateral displacement and bending moments increased up to ninefold compared with lateral-only conditions, while vertical load carried by the raft decreased from 20 % to 16.5 %. Changing the construction sequence by excavating the deeper tunnel first (StackTwinTS, StackTwinBS, StackTwinUS) resulted in larger lateral movements and tilting (up to 0.77 %) due to progressive stiffness degradation in upper soil layers. These findings demonstrate that the tunnelling sequence critically governs the deformation mechanisms and stability of battered piled raft systems, with the deeper-first sequence leading to substantial soil-structure interaction.

在人口密集的城市地区，对地下空间的需求不断增加，导致双堆式隧道的建设，与附近的桩基础产生复杂的土-结构相互作用。采用三维耦合固结有限元分析方法，研究了双叠垛隧道开挖对软粘土（2 × 2）桩筏系统性能的影响。一个发育不良的粘土模型被用来捕捉土壤刚度退化和应力路径依赖的行为，通过实验室测试校准并根据离心机数据进行验证。第一条隧道在桩身附近开挖，第二条隧道在桩趾附近、桩趾下方和筏板下方不同深度开挖（分别用StackTwinST、StackTwinSB和StackTwinSU表示）。附加分析考察了竖向横向荷载条件和施工顺序组合的影响。结果表明，第一次隧道开挖引起应力释放和动剪刚度退化，使上桩部分轴阻力降低28%。第二次隧道开挖增加了变形，特别是在筏板下方（StackTwinSU），最大横向位移为桩径的8.6%，筏板倾斜为0.64%。在联合荷载作用下，筏体的横向位移和弯矩增加了9倍，而筏体所承受的垂直荷载从20%下降到16.5%。通过先开挖较深的隧道（StackTwinTS、StackTwinBS、StackTwinUS）来改变施工顺序，由于上部土层的刚度逐渐退化，导致较大的横向移动和倾斜（高达0.77%）。这些发现表明，掘进顺序对破碎桩筏体系的变形机制和稳定性起着关键的控制作用，深优先顺序导致了大量的土-结构相互作用。

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引用次数: 0

The effect of selecting different stress states in laboratory tests on the predicted permanent deformation of soils 室内试验中选择不同应力状态对土体永久变形预测的影响

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-18 DOI: 10.1016/j.trgeo.2025.101856

João Victor Lima Alencar , Alfran Sampaio Moura , Juceline Batista dos Santos Bastos , Iuri Sidney Bessa , Jorge Barbosa Soares , Moises Braga Martins , Lucas Feitosa de Albuquerque Lima Babadopulos

Modeling permanent deformation (PD) in pavement sublayer materials is essential for predicting pavement performance. The present study evaluated the influence of stress state, by means of the stress pair (confining stresses, σ₃, and deviator stresses, σ_d) considered on the calibration of a permanent deformation model widely used in Brazil. A total of 54 repeated load triaxial (RLT) tests were performed on 6 different soils, each subjected to 9 stress pairs, resulting in 130 combinations per material. Model coefficients were obtained by multiple linear regression. The results indicated that reducing the number of stress pairs improves the coefficients of determination (R²), but may compromise the model’s global predictive capacity, especially for pairs not included in the fitting. In 61% of cases analyzed, predictions fell outside the fitted range, highlighting the model’s sensitivity to pair selection. Some coefficients showed high variability, with differences exceeding 100% even for the same material, compromising their physical interpretation. Application of this methodology to literature data confirmed these trends and showed that different stress pair selection significantly affects the regression coefficients, even when R² values are high. Numerical modeling with MeDiNa software reinforced the practical relevance of these findings, revealing that changes in the coefficients of just one layer resulted in differences of up to 22% in total pavement deformation and 92% in the deformation of the base layer. It is concluded that defining technical criteria for stress pair selection is essential for consistent predictions. Further studies are recommended to deepen the understanding of pavement stresses and their impact on permanent deformation.

路面子层材料的永久变形（PD）建模是预测路面性能的关键。本文利用应力对（围应力σ3和偏应力σd）对巴西广泛使用的永久变形模型进行了标定，评价了应力状态对模型标定的影响。在6种不同的土壤上进行了54次重复加载三轴（RLT）试验，每个试验受到9个应力对，每种材料产生130种组合。通过多元线性回归得到模型系数。结果表明，减少应力对的数量提高了决定系数（R2），但可能会损害模型的全局预测能力，特别是对未包括在拟合中的应力对。在分析的61%的案例中，预测超出了拟合范围，突出了模型对配对选择的敏感性。有些系数表现出很高的变异性，即使对于相同的材料，差异也超过100%，从而影响了它们的物理解释。将该方法应用于文献数据证实了这些趋势，并表明即使在R2值很高的情况下，不同的应力对选择也显著影响回归系数。使用MeDiNa软件进行的数值模拟强化了这些发现的实际相关性，揭示了仅一层系数的变化就会导致路面总变形量的差异高达22%，而基础层变形量的差异高达92%。结论是，确定应力对选择的技术标准对于一致性预测至关重要。建议进一步研究以加深对路面应力及其对永久变形的影响的理解。

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引用次数: 0

Deformation and degradation behaviour of coal-fouled tyre chips intermixed steel slag ballast under cyclic loading 循环荷载下煤屑混合钢渣压载物的变形与降解行为

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-17 DOI: 10.1016/j.trgeo.2025.101869

Atif Hussain , Syed Khaja Karimullah Hussaini , Buddhima Indraratna , Yujie Qi

Steel slag and tyre chips are two waste products with potential for sustainable use in railway tracks.

While the previous studies have primarily focused on the benefits of utilizing steel slag as railway subballast, yet its suitability as railway ballast with and without tyre chips (TC) has not been comprehensively investigated. Moreover, the possible effect of coal fouling on the performance of TC-intermixed steel slag ballast is yet to be studied. Therefore, the current study assessed the influence of TC on the performance of slag-granite ballast mixture under coal-fouled condition using large-scale track simulation test (TST) and constant-head permeability apparatus. TST results indicated that vertical and lateral deformations of ballast increased, while the track stiffness (k) and ballast breakage index (BBI) decreased with the increase in proportion of tyre chips. The threshold content of tyre chips to be mixed with steel slag ballast (SSB) is identified as 10%. The study further established that the addition of coal leads to an increase in deformations, while reducing BBI of TC intermixed slag-granite ballast. Moreover, the addition of coal causes a significant reduction in hydraulic conductivity of the TC intermixed ballast. Further, the critical value of void contamination index is determined to be 25%.

钢渣和轮胎碎片是两种具有可持续利用潜力的废物。以往的研究主要集中在钢渣作为铁路载道子的效益上，但对其作为铁路载道子的适用性和不含轮胎屑的适用性研究较少。此外，煤结垢对tc -混钢渣压载物性能的可能影响还有待研究。因此，本研究采用大型轨道模拟试验（TST）和恒水头渗透仪，评估了煤污染条件下TC对炉渣-花岗岩压载混合物性能的影响。TST结果表明，随着轮胎碎片比例的增加，压载物的纵向和横向变形增加，轨道刚度(k)和压载物破碎指数（BBI）降低。确定钢渣镇流器（SSB）混合轮胎碎屑的阈值含量为10%。研究进一步证实，煤的加入使TC混渣-花岗岩压载物的变形增加，同时降低了BBI。煤的加入使TC混压载水导率显著降低。进一步确定孔隙污染指数临界值为25%。

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引用次数: 0

A spectral element-based dynamic model for train-track-tunnel-soil interaction 基于谱元的列车-轨道-隧道-土壤相互作用动力学模型

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-17 DOI: 10.1016/j.trgeo.2025.101870

Liu Pan , Lei Xu , Yan Bin , Chen Mei

To address the challenges of complex modeling and low computational efficiency in the train-track-tunnel-soil (TTTS) system, this study develops a TTTS dynamic interaction model based on the spectral element method (SEM). To accurately described the complex geometry of the tunnel-soil system, this research employs iso-parameter hexahedral and triangular prism spectral elements to simulate the tunnel and surrounding soil, respectively, and describes the tunnel-soil interaction utilizing multiscale coupling method. Leveraging the low-frequency nature of infrastructure vibration, this study introduces Gaussian precise integration method, combined with multi-step hybrid solution, enables accurate resolution of infrastructure vibration with arbitrary integration step. The reliability of the proposed model and solution method is validated through comparison with the FEM model and general solution method. Subsequently, the aforementioned model is applied to the dynamic analysis of the TTTS system to investigate the ground vibration distribution induced by the train, and to examine the effects of the TTTS system parameters on the ground vibration in terms of time–frequency domain vibration and vibration level.

针对列车-轨道-隧道-土壤（TTTS）系统建模复杂、计算效率低的问题，建立了基于谱元法（SEM）的TTTS动态相互作用模型。为了准确描述隧道-土系统的复杂几何结构，本研究采用等参数六面体和三角棱镜光谱单元分别模拟隧道和周围土体，并利用多尺度耦合方法描述隧道-土相互作用。利用基础设施振动的低频特性，引入高斯精确积分法，结合多步混合求解，实现任意积分步长的基础设施振动精确解析。通过与有限元模型和一般求解方法的比较，验证了所提模型和求解方法的可靠性。随后，将上述模型应用于TTTS系统的动力学分析，研究列车引起的地面振动分布，并从时频域振动和振动水平两方面考察TTTS系统参数对地面振动的影响。

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引用次数: 0

Erosion mechanism of interlayer soils under different seepage directions: a CFD-DEM perspective 不同渗流方向下层间土侵蚀机理的CFD-DEM研究

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-17 DOI: 10.1016/j.trgeo.2025.101863

Guoqing Cai , Xianfeng Diao , Yinghui Lv , Ning Li , Chao Hu

Currently, research on the erosion-induced deformation of interlayer soils under seepage action remains at the macroscopic level, with insufficient understanding of the underlying microscopic mechanisms behind the observed macroscopic deformations. Therefore, this study, based on a Computational Fluid Dynamic − Discrete Element Method (CFD-DEM) coupled method, investigates the macroscopic deformation process and the evolution of the microscopic contact mechanics of interlayer soils during seepage, considering the effects of different seepage directions and hydraulic gradients. The results show that, parallel seepage along the contact surface, due to the absence of a coarse particle layer as a barrier, results in greater particle loss and deeper impact. The migration of fine particles forms cavities, triggering slippage and settlement of the upper coarse particle layer. The contact forces around these cavities are weak and sparse, posing a risk for deformation and collapse of the structure. In the initial stage of seepage, the vertical contact forces weaken, promoting particle migration and causing settlement of the upper layers. Packing and clogging increase the contact forces, restricting the movement of fine particles, while the stress concentration that forms allow the coarse particles to provide stable support, leading to stabilization of the settlement. Seepage disrupts particle connectivity, causing an uneven distribution of contact forces. After the seepage ends, a stress redistribution occurs, and the collapse triggered by the cavities is more likely to cause overall structural changes, ultimately resulting in a significant anisotropic distribution of the contact forces.

目前，对渗流作用下层间土侵蚀变形的研究还停留在宏观层面，对观测到的宏观变形背后的微观机制认识不足。因此，本研究基于CFD-DEM耦合方法，考虑不同渗流方向和水力梯度的影响，研究层间土在渗流过程中的宏观变形过程和微观接触力学演化。结果表明，由于没有粗颗粒层作为屏障，沿接触面平行渗流，颗粒损失更大，冲击更大；细颗粒的迁移形成空腔，引发上部粗颗粒层的滑移和沉降。这些空腔周围的接触力很弱且稀疏，有造成结构变形和倒塌的危险。在渗流初期，竖向接触力减弱，促进颗粒迁移，引起上层沉降。堆积和堵塞增加了接触力，限制了细颗粒的移动，而形成的应力集中使粗颗粒提供稳定的支撑，从而使沉降稳定。渗流破坏了颗粒的连通性，导致接触力分布不均匀。渗流结束后，发生应力重分布，由空腔引发的坍塌更容易引起整体结构变化，最终导致接触力呈现明显的各向异性分布。

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引用次数: 0

The influence of tunnel floor heave induced by high water pressure on the mechanical response of ballastless track 高水压下隧道底鼓对无砟轨道力学响应的影响

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-17 DOI: 10.1016/j.trgeo.2025.101865

Xuhao Cui , Yapeng Liu , Bowen Du , Hong Xiao , Hongbin Xu , Yang Wang , Yihao Chi

Tunnels in complex geological and high water pressure environments are prone to diseases such as tunnel floor heave (TFH), which seriously affects the operation and safety of high-speed railways. Water is a key contributing factor to TFH. By applying radial loads and constraint conditions to the tunnel base, the confining pressure effect caused by high water pressure and water-induced mudstone swelling on the tunnel base is simulated, and a tunnel base structure-load model is established. Furthermore, a refined finite element simulation analysis model considering the cohesive zone model and concrete damage plastic is developed to study the influences of different confining pressures, confining pressure ranges, and inverted arch thicknesses on the deformation, interlayer bonding, and interlayer gap of the track structure. The calculation results indicate that the maximum vertical deformation of the rail is positively correlated with the confining pressure and negatively correlated with the inverted arch thickness. The deformation range is closely related to the confining pressure range. The deformation reaches a maximum of 57.8 mm when the confining pressure is 2.0 MPa, the confining pressure range is 30 m, and the inverted arch thickness is 0.4 m. Bonding damage between the track slab and the backfill layer occurs at the boundary between the confining pressure zone and the non-confining pressure zone. The significant influence of insufficient inverted arch thickness on bond damage is not linear, the maximum bonding damage area increases from 45.5 m² at a thickness of 0.78 m to 75.8 m² at 0.5 m. The gaps between the backfill layer and the inverted arch are unevenly distributed laterally along the track, with the interlayer gaps curve transitioning from a “trapezoidal” shape on the outer rail side to an “M” shape on the inner rail side. The research results play an important role in the design and maintenance of ballastless tracks in tunnels under the action of TFH.

复杂地质和高压环境下的隧道易发生隧道底鼓（TFH）等病害，严重影响高速铁路的运行和安全。水是造成TFH的一个关键因素。通过对隧道基底施加径向荷载和约束条件，模拟了高水压和水致泥岩膨胀对隧道基底产生的围压效应，建立了隧道基底结构荷载模型。在此基础上，建立了考虑黏结区模型和混凝土损伤塑性的精细化有限元模拟分析模型，研究了不同围压、围压范围和仰拱厚度对轨道结构变形、层间粘结和层间间隙的影响。计算结果表明：钢轨最大竖向变形与围压正相关，与倒拱厚度负相关；变形范围与围压范围密切相关。当围压为2.0 MPa、围压范围为30 m、仰拱厚度为0.4 m时，变形最大57.8 mm。轨道板与回填层之间的粘结破坏发生在围压区与非围压区交界处。倒拱厚度不足对粘结损伤的显著影响不是线性的，最大粘结损伤面积从0.78 m厚度时的45.5 m2增加到0.5 m厚度时的75.8 m2。回填层与倒拱之间的间隙沿轨道横向分布不均匀，层间间隙曲线由外轨侧的“梯形”型向内轨侧的“M”型过渡。研究成果对隧道隧道在TFH作用下的无砟轨道设计与维护具有重要的指导意义。

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引用次数: 0

Ballast Aggregate Driven Nonlinear Environmental Stiffness in Heavy Haul Railway Fastenings: Novel Flexible Piezoelectric Sensor Monitoring 重载铁路压载骨料驱动的非线性环境刚度：新型柔性压电传感器监测

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-17 DOI: 10.1016/j.trgeo.2025.101857

Haoran Fu , Guanwen Liang , Chengpeng Hong , Duanyang Zhuang , Ruitao Tang , Jianqun Jiang

Ensuring the structural integrity of heavy-haul railway fastening systems is critical for operational safety and derailment prevention. Conventional rigid sensors suffer from bulkiness, poor embeddability, and limited dynamic performance, hindering their use in this demanding application. This study introduces a novel piezoelectric material engineered with a unibody design, offering inherent advantages of lightweight construction, flexibility, and conformability for integration into fastening components. Finite element analysis and D₃₃ coefficient testing demonstrated that this smart material achieves superior strain distribution uniformity and signal stability compared to traditional clipped PVDF sensors. A specialized stepwise polarization-edge depolarization process was developed to enhance piezoelectric polarization uniformity, thereby improving measurement accuracy. The smart PVDF material was rigorously calibrated using a high-frequency impact system, and its fatigue resistance and stiffness-sensing capability were evaluated across varying environmental conditions. Integrated directly into rubber pads within a full-scale heavy-haul railway subgrade physical model, the smart PVDF material effectively quantified the environmental stiffness of the fastening system – capturing its dynamic interaction with the rock ballast aggregate – under diverse operational conditions. Results revealed a distinct nonlinear decrease in environmental stiffness with increasing speed and load, contrasting with universal stiffness trends and highlighting the critical role of rock ballast aggregate behavior. This smart PVDF material demonstrates exceptional durability and adaptability for monitoring nonlinear environmental stiffness responses in heavy-haul railway infrastructure, enabling advanced assessment of rock ballast aggregate-fastening system interactions and providing a promising foundation for intelligent track health monitoring and early-warning systems.

确保重载铁路紧固系统的结构完整性对铁路运行安全和防止脱轨至关重要。传统的刚性传感器体积大，可嵌入性差，动态性能有限，阻碍了它们在这种要求苛刻的应用中使用。本研究介绍了一种新型的压电材料，该材料具有单体设计，具有轻量化结构，灵活性和集成到紧固部件的一致性等固有优势。有限元分析和D33系数测试表明，与传统的夹片式PVDF传感器相比，这种智能材料具有更好的应变分布均匀性和信号稳定性。为了提高压电偏振均匀性，提高测量精度，设计了一种专门的逐步极化边缘去极化工艺。智能PVDF材料使用高频冲击系统进行了严格校准，并在不同的环境条件下评估了其抗疲劳和刚度感知能力。智能PVDF材料直接集成到全尺寸重载铁路路基物理模型中的橡胶垫片中，有效地量化了紧固系统的环境刚度——捕捉其与岩石压载骨料在不同操作条件下的动态相互作用。结果显示，随着速度和载荷的增加，环境刚度呈明显的非线性下降，与通用刚度趋势形成对比，并突出了岩石压载骨料行为的关键作用。这种智能PVDF材料在监测重载铁路基础设施的非线性环境刚度响应方面表现出卓越的耐久性和适应性，能够对岩石压载骨料-紧固系统相互作用进行高级评估，并为智能轨道健康监测和预警系统提供了有希望的基础。

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引用次数: 0

Compressibility of Clays under Repetitive Loading: A New Perspective on Consolidation State, Loading Frequency, and Partially Drained Conditions 重复加载下粘土的压缩性：固结状态、加载频率和部分排水条件的新视角

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-16 DOI: 10.1016/j.trgeo.2025.101864

Jang-Un Kim, Hyunwook Choo

Many structures built on saturated clays are subjected to repetitive loads from sources such as waves, wind, and traffic. This loading can induce excess pore water pressure within saturated clays, leading to additional volumetric deformation and the long-term degradation of geostructures. This study investigated the compressibility of saturated clays under repetitive loading, focusing on the coupled effects of the initial degree of consolidation (U_i) and loading frequency (f). A newly developed loading system was used to perform tests on sand, kaolin, and Ca-bentonite specimens across a wide range of frequencies (f = 0.011, 0.046, 0.139, 0.278, 1.67, 8.33, 25, 125, and 250 mHz) and consolidation states (U_i = 0, 0.2, 0.4, 0.6, and 1.0). The results indicated that the cyclic-induced void ratio change (Δe) was highly sensitive to both U_i and f. For underconsolidated soils (U_i < 1), high-frequency loading significantly increased Δe, whereas the response was minimal and largely independent of these factors under low-frequency conditions or for normally consolidated soils (U_i = 1). This study identified three distinct drainage regimes: drained, partially drained, and undrained based on the cyclic loading ratio (T/t₁₀₀), establishing a quantitative threshold of T/t₁₀₀ ≤ 0.001 − 0.01 for the transition to pseudo-undrained behavior. Furthermore, repetitive loading was found to increase the horizontal effective stress, leading to a higher overconsolidation ratio and a corresponding reduction in post-cyclic compressibility. The findings provide new experimental evidence on the complex, coupled behaviors of saturated soils and offer critical insights for the reliable design and performance assessment of structures on soft clay deposits.

许多建在饱和粘土上的建筑物都要承受来自海浪、风和交通等来源的反复载荷。这种荷载会在饱和粘土中诱发超孔隙水压力，导致额外的体积变形和土工结构的长期退化。本文研究了饱和粘土在重复加载下的压缩性，重点研究了初始固结度（Ui）和加载频率(f)的耦合效应。采用新开发的加载系统对砂土、高岭土和钙膨润土试样进行了宽频率范围（f = 0.011、0.046、0.139、0.278、1.67、8.33、25、125和250 mHz）和固结状态（Ui = 0、0.2、0.4、0.6和1.0）的测试。结果表明，循环诱导的孔隙比变化（Δe）对Ui和f都高度敏感。对于欠固结土（Ui < 1），高频加载显著增加Δe，而低频条件下或正常固结土（Ui = 1）的响应很小，与这些因素无关。本研究根据循环加载比（T/t100）确定了三种不同的排水模式：排水、部分排水和不排水，并建立了T/t100≤0.001−0.01的定量阈值，以过渡到伪不排水行为。此外，发现重复加载增加了水平有效应力，导致更高的超固结比和相应的循环后压缩率降低。这一发现为研究饱和土的复杂耦合特性提供了新的实验证据，并为软粘土沉积物结构的可靠设计和性能评估提供了重要见解。

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引用次数: 0

A similarity model for subgrade compaction from collaborative laboratory-field tests 基于协同实验室现场试验的路基压实相似模型

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-16 DOI: 10.1016/j.trgeo.2025.101858

Xuefei Wang , Xu Liu , Jiale Li , Jianmin Zhang , Guowei Ma

Intelligent Compaction (IC) relies on high-quality datasets for accurate quality evaluation. However, the absence of sufficient field data challenges the model development. This study proposes a similarity model based on coordinated laboratory and field tests, aiming to provide theoretical basis for the dataset expansion. A spatio-temporal equivalence model is established using the dual energy-state equivalence principle to correlate the laboratory compaction time and the number of rolling passes. Multi-domain ICMVs are used to validate the similarity model quantitatively. Results show that the proposed method effectively expands the IC dataset. A compaction quality evaluation model trained on the augmented dataset shows significantly reduced prediction error and improved generalization comparing to the original model for all evaluation indexes. This work provides a theoretical basis to adopt the laboratory test to field applications, enhancing the assessment reliability of IC.

智能压缩（IC）依赖于高质量的数据集进行准确的质量评估。然而，缺乏足够的现场数据对模型的开发提出了挑战。本研究提出了一种基于实验室和现场协同试验的相似度模型，旨在为数据集扩展提供理论依据。利用双能态等效原理建立了实验室压实时间与轧制道次之间的时空等效模型。采用多域icmv对相似度模型进行定量验证。结果表明，该方法有效地扩展了集成电路数据集。在增强数据集上训练的压缩质量评价模型在所有评价指标上都比原始模型显著降低了预测误差，提高了泛化程度。为将实验室测试应用于现场，提高集成电路的评估可靠性提供了理论依据。

引用次数: 0

Experimental and theoretical study on the shield tunneling model for gas-bearing strata based on image processing 基于图像处理的含气地层盾构掘进模型的实验与理论研究

IF 5.5 2区工程技术 Q1 ENGINEERING, CIVIL

Transportation Geotechnics

Pub Date : 2025-12-16 DOI: 10.1016/j.trgeo.2025.101855

Zhi Ding , Jiao-Ming Xu , Yang Chen , Shao-Heng He

The free gas reservoirs occurring in the form of sacs are widely distributed along the southeastern coastal region of China, potentially posing significant risks during shield tunnelling. Hence, investigating the deformative mechanism of gas-bearing soils induced by shield excavation holds vital engineering significance. In this paper, physical model tests simulating gas-bearing strata were performed under varying L/D values (the ratio of the distance between shield excavation face and the sac to the tunnel diameter), with dry sand strata set as a control. The images captured during the tests were processed through PIV (Particle Image Velocimetry) analysis. It can be found that the variation regarding support pressure and pore pressure of fluid sac was primarily demarcated by the limiting state of the excavation, exhibiting two distinct phases in each test. Face instability occurred more rapidly in gas-bearing strata, the failure area evolved from an initial configuration of a “triangle and rectangle” to a final distribution resembling two interrelated trapezoids. The curves of surface settlement progressively exhibit a characteristic of groove shape as the displacement of tunnel face increased, and oblique photogrammetry technique was then adopted in this study to achieve three-dimensional reconstruction of the settlement pit. For a larger value of L/D, the influencing area induced by shield excavation varies within a broader range while the maximum deformation and volume is relatively small. By improving column hole shrinkage theory, a theoretical formulation accounting for soil loss was derived to accurately predict surface deformation in gas-bearing strata. On this basis, the effects of tunnel depth and excavation radius on surface deformation were analysed.

在中国东南沿海地区，以囊状形式赋存的游离气藏广泛分布，在盾构隧道施工中具有较大的潜在风险。因此，研究盾构开挖引起含气土的变形机理具有重要的工程意义。本文以干砂地层为对照，在不同的L/D值（盾构开挖工作面与硐室之间的距离与隧道直径之比）条件下进行了含气地层的模拟物理模型试验。测试过程中捕获的图像通过PIV（粒子图像测速）分析进行处理。可以发现，支护压力和液囊孔隙压力的变化主要以基坑的极限状态为界限，在每次试验中表现出两个不同的阶段。在含气地层中，工作面失稳发生得更快，破坏区域从最初的“三角形和矩形”形态演变为最终的“两个相互关联的梯形”形态。随着巷道工作面位移的增大，地表沉降曲线逐渐呈现沟槽状特征，本研究采用斜向摄影测量技术实现沉降坑的三维重建。当L/D值较大时，盾构开挖的影响区域变化范围较大，而最大变形量和最大体积相对较小。通过对柱孔收缩理论的改进，推导出考虑土壤流失量的理论公式，以准确预测含气地层地表变形。在此基础上，分析了隧道深度和开挖半径对地表变形的影响。

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引用次数: 0