Tunnelling and Underground Space Technology最新文献_第3页

A two-stage robust optimization model for underground container logistics system investment under carbon tax and subsidies policies 碳税和补贴政策下地下集装箱物流系统投资的两阶段稳健优化模型

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-18 DOI: 10.1016/j.tust.2026.107444

Miaomiao Sun , Chengji Liang , Yu Wang , Nikolai Bobylev

Rapid urbanization is causing severe traffic congestion and carbon emissions. Leveraging underground space for Underground Container Logistics Systems (UCLS) is a promising solution, but its adoption is hindered by substantial capital investment barriers. To overcome this hurdle, government interventions, such as carbon taxes and subsidies, are considered critical economic levers. However, the quantitative impact of these combined policies on an operator’s investment decision, especially under demand uncertainty, remains unclear. This study develops a Two-Stage Robust Optimization (2S-RO) model from the port operator’s perspective to address this gap. The model determines the optimal strategic investment in UCLS routes (Stage 1) and the corresponding tactical container flow allocation (Stage 2), minimizing total costs under the worst-case demand scenario characterized by a budget-of-uncertainty set. The model is solved using a Column-and-Constraint Generation (C&CG) algorithm. A case study based on the Shanghai port region, consisting of 2 logistics parks and 3 container ports with annual demand of 20,500 Twenty-foot Equivalent Unit (TEU), analyzes 15 policy scenarios. Results reveal a policy combination “tipping point” effect: neither carbon tax nor subsidy alone triggers UCLS investment, but their combination at a threshold intensity (15 yuan/kg carbon tax + 15 % subsidy) makes UCLS economically viable, achieving 16.13 % cost savings, 59.08 % carbon emission reduction (from 2,847.6 to 1,165.2 tons/year), and a 2.9-year investment payback period. Flow allocation analysis shows that at this tipping point, 48.8 % of container flows shift from road transport to UCLS (37.6 % to shallow systems and 11.2 % to deep systems). Sensitivity analysis demonstrates that demand uncertainty, investment cost variations, and carbon emission caps significantly influence investment decisions: higher uncertainty requires stronger policy support, ±30 % cost variations substantially alter project viability, and emission caps must be set below 2000 tons/year (70 % of baseline) to effectively drive investment. This research provides a quantitative framework for operators to evaluate UCLS projects under uncertainty and offers evidence-based policy design guidance for policymakers, contributing to sustainable urban underground space utilization and port logistics decarbonization.

快速的城市化造成了严重的交通拥堵和碳排放。利用地下空间进行地下集装箱物流系统（UCLS）是一个很有前途的解决方案，但其采用受到大量资本投资壁垒的阻碍。为了克服这一障碍，政府干预，如碳税和补贴，被认为是关键的经济杠杆。然而，这些综合政策对运营商投资决策的定量影响，特别是在需求不确定的情况下，仍然不清楚。本研究从港口运营商的角度开发了一个两阶段稳健优化（2S-RO）模型来解决这一差距。该模型确定了UCLS路线的最优战略投资（阶段1）和相应的战术集装箱流量分配（阶段2），在以不确定预算集为特征的最坏需求情景下，使总成本最小化。该模型采用列约束生成（C&；CG）算法求解。以上海港区为例，分析了15种政策情景。上海港区由2个物流园区和3个集装箱港口组成，年需求量为20,500标准箱。结果表明，政策组合存在“引爆点”效应：碳税和补贴都不能单独触发UCLS投资，但在阈值强度（15元/kg碳税+ 15%补贴）下，两者组合使UCLS具有经济可行性，成本节约16.13%，碳排放量减少59.08%（从2847.6吨/年减少到1165.2吨/年），投资回收期为2.9年。流量分配分析表明，在这个临界点，48.8%的集装箱流量从公路运输转向UCLS（37.6%转向浅层系统，11.2%转向深层系统）。敏感性分析表明，需求不确定性、投资成本变化和碳排放上限显著影响投资决策：较高的不确定性需要更强的政策支持，±30%的成本变化将大大改变项目的可行性，排放上限必须设定在2000吨/年以下（基线的70%）才能有效推动投资。本研究为运营商在不确定性条件下评估UCLS项目提供了定量框架，为决策者提供了基于证据的政策设计指导，有助于城市地下空间可持续利用和港口物流脱碳。

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引用次数: 0

Temporal psychological and physiological responses to 120-hour isolation in an underground rescue chamber: A preliminary study 在地下救援室隔离120小时后的暂时心理和生理反应：初步研究

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-06 DOI: 10.1016/j.tust.2025.107442

Jie Zhang , Ligang Tan , Xueliang Xu , Cuibin Xie , Xuanhui Xu , Zhizhong Li , Feng Wang

The development of underground space has become a strategic focus in both infrastructure engineering and urban sustainability planning, drawing increasing attention to human health. While prior studies have primarily examined the health effects of routine exposure to controlled urban underground environments, their findings cannot be directly applied to emergency rescue chambers. Existing research on rescue chambers has been limited to no longer than 48-hour exposures, with a few thermal studies extending to 106 h but lacking analyses of psychological and physiological responses. Moreover, the moderating effects of individual characteristics have not been well understood. To address this gap, this study conducted a 120-hour simulated experiment with eight male participants to investigate how exposure duration interacts with individual characteristics to influence human psychological and physiological responses. The sample size was constrained by the rated capacity of the rescue chamber, and multiple runs were not allowed for this exploratory study due to participant health and safety concerns. The results showed that positive emotion and team relationship deteriorated over time, with a faster decline for participants with higher openness and mental health. Furthermore, positive emotion mediated team relationship changes, highlighting the critical role of affective states in maintaining interpersonal cohesion. Notably, participants with better mental health experienced more stable interpersonal dynamics, even in the face of emotional fluctuations. While no significant changes were observed in heart rate, heart rate variability, and breathing rate, some correlations were detected between physiological and psychological measures. Overall, these findings contribute to empirical evidence on human adaptation to confined underground environments and offer practical implications for rescue chamber design (e.g., increasing space and incorporating privacy features to sustain positive emotion and preserve team cohesion) and personnel training (e.g., developing psychological resilience, teamwork skills, and stress management strategies to prepare workers for prolonged confinement). However, the findings should be considered exploratory findings due to the small sample size. Future research with larger and more diverse samples in ecologically valid settings is warranted to further validate these findings.

地下空间的开发已成为基础设施工程和城市可持续发展规划的战略重点，日益引起人们对人类健康的关注。虽然先前的研究主要是检查常规暴露于受控制的城市地下环境对健康的影响，但他们的发现不能直接应用于紧急救援室。现有的救援舱研究仅限于不超过48小时的暴露，少数热研究延长至106小时，但缺乏对心理和生理反应的分析。此外，个体特征的调节作用尚未得到很好的理解。为了解决这一差距，本研究对8名男性参与者进行了120小时的模拟实验，以研究暴露时间如何与个体特征相互作用，从而影响人类的心理和生理反应。样本量受到救援室额定容量的限制，由于参与者的健康和安全考虑，本探索性研究不允许多次运行。结果表明，积极情绪和团队关系随着时间的推移而恶化，开放度和心理健康程度越高的参与者的积极情绪和团队关系下降越快。此外，积极情绪介导了团队关系的变化，强调了情感状态在维持人际凝聚力方面的关键作用。值得注意的是，心理健康状况较好的参与者经历了更稳定的人际关系动态，即使面对情绪波动。虽然在心率、心率变异性和呼吸频率方面没有观察到明显的变化，但在生理和心理测量之间发现了一些相关性。总的来说，这些研究结果为人类对密闭地下环境的适应提供了经验证据，并为救援室的设计（如增加空间和结合隐私特征以维持积极情绪和保持团队凝聚力）和人员培训（如培养心理弹性、团队合作技能和压力管理策略，以使工人为长时间的禁闭做好准备）提供了实际意义。然而，由于样本量小，研究结果应被视为探索性研究结果。未来的研究将在生态有效的环境中进行更大、更多样化的样本，以进一步验证这些发现。

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引用次数: 0

An interpretable and adaptive tunnel water inflow prediction method using data augmentation and AHP-Enhanced OP-LightGBM 基于数据增强和AHP-Enhanced OP-LightGBM的可解释自适应隧道涌水预测方法

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-08 DOI: 10.1016/j.tust.2026.107445

Jingqi Cui , Shunchuan Wu , Haiyong Cheng , Xiaowei Hou , Jiaxin Wang , Weihua Liu , Chaoqun Chu

Accurate prediction of tunnel water inflow is critical for ensuring construction safety and risk control in tunnel engineering. However, traditional regression methods face significant challenges, including limited sample sizes, imbalanced data, complex feature interactions, and difficulty in engineering deployment. To address these issues, this study proposes an intelligent prediction framework that integrates data augmentation, model optimization, interpretability, and online deployment, and additionally possesses strong adaptability to dynamic field conditions. First, the SMOGN undersampling method is employed to balance and augment the training dataset, effectively expanding sparse samples and suppressing the influence of outliers, thereby enhancing the model’s generalization ability. Subsequently, LightGBM is improved through Optuna-based hyperparameter optimization and Analytic Hierarchy Process (AHP)-based feature weight adjustment, forming the AHP-OP-LightGBM hybrid model. This approach reduces prediction error by 15.89 % while aligning feature weights more closely with physical constraints. Compared with conventional optimization strategies, the model demonstrates superior capability in representing hydrogeological characteristics due to the dual mechanism of automated hyperparameter tuning and feature weight correction. Correlation analysis and SHAP-based interpretability further clarify the nonlinear synergistic mechanisms governing the coupled geomechanical-hydrological processes controlling tunnel water inflow. To support engineering application, a cloud-deployed online prediction system is developed using web technologies, integrating SHAP for transparent decision support. Additionally, an incremental learning module is incorporated to accommodate dynamic data variations. Validation using a small set of local incremental samples yields a maximum prediction error of only 1.9169 m³/h, demonstrating strong compatibility and accuracy across different engineering scenarios. Comparative experiments show that, on average, the proposed model reduces prediction error by 39.65 % and improves fitting accuracy by 18.43 % compared with traditional regression methods. Overall, this study provides a high-precision, interpretable, and generalizable intelligent solution for predicting tunnel water inflow under complex geological conditions.

隧道涌水的准确预测是保证隧道工程施工安全和风险控制的关键。然而，传统的回归方法面临着样本量有限、数据不平衡、特征交互复杂、工程部署困难等重大挑战。针对这些问题，本研究提出了一种集数据扩充、模型优化、可解释性和在线部署于一体的智能预测框架，并对动态现场条件具有较强的适应性。首先，采用SMOGN欠采样方法对训练数据集进行平衡和扩充，有效扩展稀疏样本，抑制离群值的影响，从而增强模型的泛化能力。随后，通过基于optuna的超参数优化和基于AHP （Analytic Hierarchy Process）的特征权值调整对LightGBM进行改进，形成AHP- op -LightGBM混合模型。该方法将预测误差降低了15.89%，同时将特征权重与物理约束更紧密地对齐。与传统优化策略相比，该模型具有自动超参数整定和特征权值校正的双重机制，具有较好的表征水文地质特征的能力。相关分析和基于shap的可解释性进一步阐明了控制隧道涌水的耦合地质力学-水文过程的非线性协同机制。为了支持工程应用，利用web技术开发了一个云部署的在线预测系统，集成了SHAP以提供透明的决策支持。此外，还包含了一个增量学习模块，以适应动态数据变化。使用一小组局部增量样本进行验证，最大预测误差仅为1.9169 m3/h，显示了不同工程场景的强兼容性和准确性。对比实验表明，与传统回归方法相比，该模型的预测误差平均降低了39.65%，拟合精度平均提高了18.43%。总体而言，本研究为复杂地质条件下的隧道涌水预测提供了高精度、可解释性和通用性的智能解决方案。

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引用次数: 0

Numerical study of smoke movement and heat confinement under the influence of the stack effect in passages with horizontal and inclined sections 水平段和倾斜段通道中烟囱效应影响下烟流和热约束的数值研究

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-12 DOI: 10.1016/j.tust.2026.107447

Zekun Li , Georgios Maragkos , Miaocheng Weng , Fang Liu , Bart Merci

Smoke propagation in passages with combined horizontal and inclined sections is examined through theoretical analysis and CFD simulations. The study explores the effects of heat release rate (HRR), passage geometry, and fire source location on buoyancy-driven flow, ventilation behavior, and upstream smoke flow, including heat outflow. Results show that geometric parameters such as ceiling height and elevation height play a crucial role in governing the smoke movement patterns. A critical induced airflow velocity, called ‘heat confinement velocity’, is identified, beyond which upstream heat outflow is effectively suppressed. Beyond the parameters mentioned above, it also accounts for the influence of fire position, especially near the lower entrance and near inclined sections. Additionally, a simplified theoretical model is established to estimate the induced airflow velocity, as well as a scaling relationship between this induced velocity and the heat confinement velocity, for HRR values above and below the critical value as classically defined for tunnels. Finally, a significant impact is demonstrated if the location of the fire is close to an inclined section of the passage, with much weaker upstream smoke flow and much stronger flow into the inclined section of the passage. These findings are useful for performance-based smoke control design in inclined and semi-inclined underground spaces.

通过理论分析和CFD模拟，研究了水平段和倾斜段组合通道中的烟雾传播。该研究探讨了热释放率（HRR）、通道几何形状和火源位置对浮力驱动流动、通风行为和上游烟流（包括热流出）的影响。结果表明，顶棚高度和仰角高度等几何参数对烟雾运动模式起着至关重要的控制作用。确定了一个临界诱导气流速度，称为“热约束速度”，超过该速度上游的热流出被有效抑制。除上述参数外，还考虑了火力位置的影响，特别是靠近下入口和靠近倾斜段。此外，建立了简化的理论模型，用于估计隧道HRR值高于和低于经典定义的临界值时的诱导气流速度，以及诱导气流速度与热约束速度之间的标度关系。最后，如果火灾的位置靠近通道的倾斜部分，则会产生显著的影响，上游的烟雾流要弱得多，而进入通道倾斜部分的烟雾流要强得多。研究结果可为倾斜和半倾斜地下空间的性能控制设计提供参考。

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引用次数: 0

A new rock cutting and splitting method for hard-rock excavation: methodology, scaled model test and numerical modelling, and field validation 硬岩开挖切割劈裂新方法：方法学、比例模型试验与数值模拟及现场验证

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-24 DOI: 10.1016/j.tust.2026.107477

Jung-Woo Cho , Hoyoung Jeong , Sang-Hwa Yu , Hee-Suk Lee

Rock cutting and splitting is a new mechanical excavation method that consists of two steps: cutting with a saw and splitting with a wedge. The rock is cut to a prescribed depth in the first step, then each block is split by inserting a wedge into the cut. The main failure mechanism is tensile crack propagation from the base of the block towards the free face. We introduce an analytic solution to estimate the required indenting force. A series of scaled model tests confirmed that effective block separation occurs when the spacing-to-depth ratio is <2.0. Numerical models reproduce the tensile fracturing mechanism and validate the experimental results. Finally, in situ excavation tests on a granite slope and a simulated tunnel face demonstrate the applicability of the method to real-world situations. In hard rock (UCS > 100 MPa), the net cutting rate of CS method was 20 %–30 % higher than that predicted for roadheaders and more than 600 % higher than that of impact hammers. Photogrammetric surveys confirmed that the block shape matches the intended shape, suggesting the potential reuse of the blocks as construction material.

岩石切割劈裂是一种新型的机械开挖方法，主要由锯切和楔劈两步组成。在第一步中，岩石被切割到规定的深度，然后通过在切口中插入楔子来分割每个块。主要破坏机制是张拉裂纹从块体底部向自由面扩展。我们引入了一个解析解来估计所需的压痕力。一系列比例模型试验证实，当距深比为2.0时，块体分离效果明显。数值模型模拟了拉伸致裂机理，验证了实验结果。最后，对花岗岩边坡和模拟隧道工作面进行了现场开挖试验，验证了该方法对实际情况的适用性。在硬岩（UCS > 100 MPa）中，CS法的净切削率比掘进机的预测切削率高20% - 30%，比冲击锤的预测切削率高600%以上。摄影测量调查证实了街区的形状符合预期的形状，这表明这些街区有可能被用作建筑材料。

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引用次数: 0

Thermomechanical behavior and damage mechanism of the lining backfill body of high-temperature thermal energy storage reservoirs in mines 矿山高温储热库衬砌充填体热力学行为及损伤机理

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-22 DOI: 10.1016/j.tust.2025.107409

Gang Xu , Pengfei Shan , Xingping Lai , Qinxin Hu , Shangtong Yang , Huicong Xu

The construction of underground thermal energy storage (UTES) systems using the space of abandoned mines is one of the most promising large-scale energy storage methods for the future. However, thermal fatigue damage caused by high-temperature environments may trigger potential destabilization of the backfill body that surround the thermal energy storage reservoir. It is therefore worthwhile to investigate the mechanism of mechanical weakening of the backfill body due to temperature effects. In this study, backfill body samples were subjected to heat treatment at six temperature levels and static mechanical testing. The thermomechanical behavior of the backfill body at different heating temperatures was investigated. Through acoustic emission (AE) technology and scanning electron microscope (SEM), the damage evolution law and instability precursors of the backfill body under thermomechanical effects were analyzed, revealing the crack propagation behavior and damage weakening mechanism of the backfill body. The results show that when the heating temperature rose from 25 °C to 500 °C, the compressive strength and elastic modulus of the backfill body decreased by 78.61 % and 84.21 %, and the peak strain increased by 62.54 %. High temperatures significantly weaken the mechanical properties of backfill body samples, promote plastic softening in the samples, and increase their ductility and deformation capacity. This is microscopically attributed to the structural damage to the backfill body caused by the progressive decomposition of ettringite, calcium silicate hydrate, and calcium hydroxide in high-temperature environments. This effect is visible in the SEM images of the microstructure of the backfill body and is dominated by the temperature level. The evolution patterns of AE counts and b-values effectively characterize the damage process of the backfill body and provide valuable early warning information for its fracture instability. As the temperature increased, the proportion of shear cracks rose from 31.72 % to 74.18 %. High temperatures significantly accelerate the formation and propagation of shear cracks, ultimately leading to a tensile-shear hybrid failure in the backfill body dominated by shear cracking. The research results provide theoretical references for the reinforcement design and disaster warning of defect-sensitive areas in thermal energy storage reservoir in UTES projects.

利用废弃矿山空间建设地下储热系统是未来最有前途的大规模储能方法之一。然而，高温环境引起的热疲劳损伤可能引发储热库周围充填体的潜在失稳。因此，对温度作用下充填体力学弱化的机理进行研究是有价值的。在本研究中，回填体试样进行了六个温度水平的热处理和静态力学测试。研究了充填体在不同加热温度下的热力学行为。通过声发射（AE）技术和扫描电镜（SEM）技术，分析了热力学作用下充填体的损伤演化规律和失稳前兆，揭示了充填体的裂纹扩展行为和损伤弱化机制。结果表明：当加热温度从25℃升高到500℃时，充填体抗压强度和弹性模量分别下降78.61%和84.21%，峰值应变增加62.54%；高温显著削弱了充填体试样的力学性能，促进了充填体试样的塑性软化，提高了充填体试样的延性和变形能力。微观上是由于钙矾石、水合硅酸钙和氢氧化钙在高温环境下不断分解，对充填体造成结构破坏。这种影响在回填体微观结构的SEM图像中可见，并且受温度水平的支配。声发射计数和b值的演化规律有效表征了充填体的破坏过程，为充填体的断裂失稳提供了有价值的预警信息。随着温度的升高，剪切裂纹的比例从31.72%上升到74.18%。高温显著加速了剪切裂纹的形成和扩展，最终导致充填体以剪切裂纹为主的拉剪复合破坏。研究结果可为UTES工程蓄热库区缺陷敏感区的加固设计和灾害预警提供理论参考。

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引用次数: 0

A study on the impact of tunnel cross-sectional shape on the accidental dispersion and explosion characteristics of hydrogen 隧道截面形状对氢气意外扩散和爆炸特性影响的研究

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-30 DOI: 10.1016/j.tust.2026.107462

Lei Baiwei , Guo Zekai , Li Xiaotang , Guo Changna

To analyze the impact of different tunnel cross-sectional geometries on the accidental dispersion and explosion characteristics of hydrogen, In this study, we utilize the CFD tool GASFLOW-MPI to numerically simulate the leakage, dispersion, and combustion of hydrogen in a full-scale tunnel. Two different tunnel cross-sectional structures are considered: arched roof tunnel and trapezoidal roof tunnel. The DES turbulence models simulate the hydrogen leakage and combustion processes. The characteristics of hydrogen dispersion distribution, concentration stratification, flame acceleration zones, etc., under different tunnel structures are compared and analyzed. Additionally, the peak overpressure generated by hydrogen explosion under both tunnel structures is calculated. The results show that the arched roof tunnel has a wider dispersion range in the tunnel length direction, promoting the mixing of a larger amount of hydrogen with fresh air. However, the arched roof tunnel top is also more prone to forming high-concentration hydrogen accumulation zones in local areas, posing a risk of flame acceleration and detonation transition. The trapezoidal roof tunnel has a larger dispersion distance in the vertical and tunnel width directions, resulting in a more uniform mixing of the hydrogen cloud, and the risk of deflagration-to-detonation transition is relatively lower. The damage to the tunnel structure and personnel caused by the deflagration overpressure of the dispersed hydrogen cloud was evaluated. The results show that the arched roof tunnel has a larger range and more severe overpressure and high-temperature damage to the tunnel structure and equipment in the top space. The middle and lower spaces of the trapezoidal roof tunnel cause more damage to the personnel located there. This study can provide theoretical support for improving the prevention of hydrogen leakage accidents in highway tunnels, the ability to respond to emergencies, and tunnel design and management.

为了分析不同的隧道截面几何形状对氢气意外扩散和爆炸特性的影响，本研究利用CFD工具GASFLOW-MPI对全尺寸隧道中氢气的泄漏、扩散和燃烧进行了数值模拟。考虑了两种不同的隧道断面结构：拱顶隧道和梯形隧道。DES湍流模型模拟了氢气泄漏和燃烧过程。对比分析了不同隧道结构下氢气弥散分布、浓度分层、火焰加速带等特征。并对两种隧道结构下氢气爆炸产生的峰值超压进行了计算。结果表明：拱顶隧道在隧道长度方向上具有更大的弥散范围，促进了大量氢气与新鲜空气的混合；然而，拱顶巷道顶部也更容易在局部区域形成高浓度的氢气聚集区，存在火焰加速和爆轰过渡的风险。梯形顶板巷道在垂直方向和巷道宽度方向上弥散距离较大，使得氢云混合更加均匀，爆燃-爆轰过渡的风险相对较低。对分散氢云爆燃超压对隧道结构和人员的危害进行了评估。结果表明：拱顶巷道顶部结构和设备的超压和高温损伤范围更大，损伤程度更严重；梯形顶板巷道的中下部空间对位于其中的人员造成较大的伤害。本研究可为提高公路隧道氢气泄漏事故的预防、应急响应能力和隧道设计管理水平提供理论支持。

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引用次数: 0

Cooling energy demand for maintaining frozen wall thickness in artificial ground freezing 人工冻结中维持冻结壁厚的冷却能量需求

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-06 DOI: 10.1016/j.tust.2025.107407

Xu Li , Rui-ming Li , Xiao-kang Li , Shuang Liu , Zheng Yang

The frozen wall thickness (E) is critical for both freezing performance and expense in artificial ground freezing (AGF), while maintaining E precisely still poses a challenge. Accordingly, this study proposes a novel concept of cooling energy demand (

{\dot{Q}}_{d}

) at which E remains stable through a numerical orthogonal test on the heat exchange between the frozen wall and the surrounding stratum. Furthermore, a comprehensive

{\dot{Q}}_{d}

prediction model is developed and validated considering the initial stratum temperature, thermal conductivity of soil particles, saturated water content, and target frozen wall radius. Results show that heat flux between frozen wall and stratum remains uniform at the steady freezing state across an arbitrary section, laying a foundation for introducing the

{\dot{Q}}_{d}

. Additionally, the initial temperature and thermal conductivity of stratum are primary factors governing

{\dot{Q}}_{d}

, with a contribution rate of 70% and 24%, respectively, while the rest are secondary factors that can be normalized. Moreover, it has been verified that the proposed

{\dot{Q}}_{d}

model achieves higher precision than empirical approaches in controlling E. Overall, this study offers not only a theoretical basis but also practical guidance for precisely controlling frozen wall thickness in AGF engineering.

在人工冻结中，冻结壁厚(E)对冻结性能和成本都至关重要，而精确保持E仍然是一个挑战。据此，本研究通过冻结墙与围岩热交换的数值正交试验，提出了在E保持稳定时的冷却能量需求（Q³d）的新概念。在此基础上，建立了考虑地层初始温度、土壤颗粒导热系数、饱和含水量和目标冻结壁半径等因素的Q / d综合预测模型，并进行了验证。结果表明：在任意截面上，冻结壁与地层之间的热流密度在稳定冻结状态下保持均匀，为引入Q / d奠定了基础。另外，地层初始温度和热导率是决定Q (d)的主要因素，贡献率分别为70%和24%，其余为次要因素，可归一化。验证了所提出的Q (d)模型在控制e方面比经验方法具有更高的精度，为AGF工程中精确控制冻结壁厚提供了理论依据和实践指导。

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引用次数: 0

Deciphering the time-dependent behavior of underground rock tunnels: Insights from a generalized non-associative thermo-viscoplastic damage model 解读地下岩石隧道的时间依赖行为：来自广义非关联热粘塑性损伤模型的见解

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-07 DOI: 10.1016/j.tust.2025.107428

Zhi-Jie Wen , Jian Tao , Yu-Jun Zuo , Xing Zhu

The time-dependent deformation of underground rock tunnels in coupled geopressure and geothermal environments poses significant challenges to sustainable resource extraction and subsurface space utilization. In this study, a novel non-associative thermo-viscoplastic damage model is proposed within the thermodynamic framework for characterizing the rock creep behavior. By integrating the temperature and damage variables directly into the free energy and energy dissipation functions, the derived yield criterion can automatically capture the pressure- and thermally-induced rock hardening/softening response. The proposed model is systematically validated by laboratory triaxial compression and creep tests, and is then applied to investigate the long-term creep performance of underground rock tunnels at different temperatures. The underlying mechanisms responsible for time-dependent tunnel deformation and cracking are quantitatively elucidated through stress-displacement-damage coupling analysis. The calculated results reveal that the surrounding rock in major principal stress directions generally exhibits limited damage but significant displacement, prone to inducing rock extrusion and bulging. In contrast, the tunnel region in minor principal stress directions will experience smaller time-dependent deformation yet severe damage accumulation, rendering it susceptible to localized rock fracturing. Moreover, elevated temperatures are shown to accelerate the creep failure of underground tunnels owing to thermally-induced rock deterioration, and the timely support measures are thus indispensable for ensuring tunnel stability in geothermal settings. The findings of our study are believed to enhance the understanding of time-dependent rock deformation in coupled thermal–mechanical conditions and can thus provide a theoretical basis for guiding the adaptive support design of deep geothermal tunnels.

地压-地热耦合环境下地下岩石隧道的时效变形对资源的可持续开采和地下空间的利用提出了重大挑战。本文在热力学框架内提出了一种新的非关联热粘塑性损伤模型来表征岩石的蠕变行为。通过将温度和损伤变量直接积分到自由能和能量耗散函数中，导出的屈服准则可以自动捕获压力和热致岩石硬化/软化响应。通过室内三轴压缩和蠕变试验对该模型进行了系统验证，并应用于不同温度下地下岩石隧道的长期蠕变特性研究。通过应力-位移-损伤耦合分析，定量地阐明了随时间变化的隧道变形和开裂的潜在机制。计算结果表明，主应力方向上的围岩一般损伤有限，但位移较大，易发生岩石挤压胀形。而在主应力较小的隧洞区域，随时间的变形较小，但损伤积累严重，容易发生局部岩石破裂。此外，高温会加速地下隧道因热致岩石劣化而发生蠕变破坏，及时采取支护措施是保证地热环境下隧道稳定的必要条件。研究结果有助于加深对热-力耦合条件下岩石变形随时间变化的认识，为指导深部地热隧道的自适应支护设计提供理论依据。

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引用次数: 0

Intelligent identification and deformation analysis of subsurface cavities in deep excavations using CNN-based inverse modeling 基于cnn逆建模的深基坑地下空腔智能识别与变形分析

IF 7.4 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Tunnelling and Underground Space Technology

Pub Date : 2026-05-01 Epub Date: 2026-01-08 DOI: 10.1016/j.tust.2025.107419

Wei Zhang , Ya-Dong Xue , Jin-Zhang Zhang , Gang Zheng , Zeng-Zhi Qian , Yu-Xin Zhai

Subsurface cavities in soft soil poses significant geotechnical challenges to the rapid expansion of urban underground spaces. This study presents a comprehensive framework for quantifying cavity-induced deformation amplification during deep excavation and develops an intelligent inversion system for cavity characterization using monitoring data. Through 1,800 finite element simulations, parametric analyses reveal that cavities located within 0.5 times the excavation depth (H_e) horizontally from the diaphragm wall and at depths of 1.5 H_e to 2.25 H_e constitute the most critical influence zone, amplifying horizontal wall displacement by up to 1.67 times and ground settlement by up to 2.2 times. K-means clustering analysis identifies five distinct settlement deformation patterns (Modes I–V) strongly correlated with cavity size and location. A convolutional neural network (CNN) based inversion model is developed to predict cavity dimensions and positions from deformation monitoring data, achieving over 85 % accuracy (R² > 0.85) on test datasets. The model demonstrates robust performance under soil parameter uncertainties modeled with random fields, maintaining acceptable prediction accuracy when spatial variability is considered. This integrated framework provides a practical tool for real-time cavity detection and risk mitigation in deep excavation projects within cavity-bearing strata, offering valuable guidance for construction safety management in complex urban geological conditions.

软土地下空腔对城市地下空间的快速扩张提出了重大的岩土工程挑战。本研究提出了一个综合框架来量化深基坑开挖过程中空洞引起的变形放大，并开发了一种利用监测数据进行空洞表征的智能反演系统。通过1800次有限元模拟，参数化分析表明，在距连续墙水平方向0.5倍开挖深度（He）范围内，深度在1.5 ~ 2.25 He范围内的空腔构成了最关键的影响区，使水平墙位移放大1.67倍，地面沉降放大2.2倍。K-means聚类分析确定了5种不同的沉降变形模式（I-V模式），这些模式与空洞的大小和位置密切相关。开发了一种基于卷积神经网络（CNN）的反演模型，从变形监测数据中预测空腔尺寸和位置，在测试数据集上实现了85%以上的精度（R2 > 0.85）。该模型在随机场模拟的土壤参数不确定性下表现出鲁棒性，在考虑空间变异性时保持可接受的预测精度。该集成框架为含空腔地层中深基坑工程的实时空腔探测和风险缓解提供了实用工具，为复杂城市地质条件下的施工安全管理提供了有价值的指导。

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引用次数: 0