期刊：
Soil Dynamics and Earthquake Engineering,2026年200:109741 ISSN：0267-7261
通讯作者：
Dongliang Meng
作者机构：
[Menggang Yang; Renkang Hu; Dongliang Meng; Wenqiang Peng] School of Civil Engineering, Central South University, Changsha, 410075, China;Earthquake Engineering Research and Test Center, Guangzhou University, Guangzhou, 510006, China;[Qiong Gao] College of Civil Engineering, Hunan City University, Yiyang, 413000, China;[Shangtao Hu] School of Civil Engineering, Central South University, Changsha, 410075, China<&wdkj&>Earthquake Engineering Research and Test Center, Guangzhou University, Guangzhou, 510006, China
通讯机构：
[Dongliang Meng] S;School of Civil Engineering, Central South University, Changsha, 410075, China
摘要：
To address the limitations of traditional passive dampers in controlling multi-level seismic excitations, the hybrid damping system, which typically incorporates various dampers, has attracted considerable interest owing to its enhanced performance. This study presents a comprehensive investigation of the Combined Viscous–Steel Damping System (CVSDS) specifically designed for the longitudinal seismic control of long-span suspension bridges. A novel dual-stage analytical model was developed to characterize the nonlinear mechanical behavior of the CVSDS, capturing the fuse-lock transition mechanism between the viscous and steel damping components. The simplified calculation approach for the supplementary damping ratio of the system was proposed and verified through numerical simulations. To validate the seismic mitigation performance of the CVSDS in realistic conditions, a series of shake table tests were conducted using a single-degree-of-freedom model that represents the longitudinal floating behavior of a suspension bridge. The results illustrate that the CVSDS can effectively reduce seismic-induced displacement by 37.9 %–60.2 % under various earthquake intensities. In particular, adjustment in the locking force allows control over the triggering sensitivity of the system, enabling tailored responses under different loading scenarios. Moreover, the proposed numerical model, which incorporates the clearance effect observed during tests, shows good agreement with experimental data, with a maximum deviation of approximately 15 %. The findings provide a practical framework for its application in long-span bridges.
To address the limitations of traditional passive dampers in controlling multi-level seismic excitations, the hybrid damping system, which typically incorporates various dampers, has attracted considerable interest owing to its enhanced performance. This study presents a comprehensive investigation of the Combined Viscous–Steel Damping System (CVSDS) specifically designed for the longitudinal seismic control of long-span suspension bridges. A novel dual-stage analytical model was developed to characterize the nonlinear mechanical behavior of the CVSDS, capturing the fuse-lock transition mechanism between the viscous and steel damping components. The simplified calculation approach for the supplementary damping ratio of the system was proposed and verified through numerical simulations. To validate the seismic mitigation performance of the CVSDS in realistic conditions, a series of shake table tests were conducted using a single-degree-of-freedom model that represents the longitudinal floating behavior of a suspension bridge. The results illustrate that the CVSDS can effectively reduce seismic-induced displacement by 37.9 %–60.2 % under various earthquake intensities. In particular, adjustment in the locking force allows control over the triggering sensitivity of the system, enabling tailored responses under different loading scenarios. Moreover, the proposed numerical model, which incorporates the clearance effect observed during tests, shows good agreement with experimental data, with a maximum deviation of approximately 15 %. The findings provide a practical framework for its application in long-span bridges.
期刊：
Journal of Vibroengineering,2025年27(4):619-637 ISSN：1392-8716
通讯作者：
Wang, FF
作者机构：
[Li, Yanchao; Jiang, Anmin; Dong, Yanchen] Hunan Urban Construct Coll, Dept Management Engn, Xiangtan 411101, Hunan, Peoples R China.;[Jiang, Anmin] Hunan Univ Sci & Technol, Sch Resource Environm & Safety Engn, Xiangtan 411201, Peoples R China.;[Wang, Feifei; Guo, Hanyang] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Wang, Feifei] Hunan City Univ, Key Lab Green Bldg & Intelligent Construct Higher, Yiyang 413000, Peoples R China.
通讯机构：
[Wang, FF ] H;Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;Hunan City Univ, Key Lab Green Bldg & Intelligent Construct Higher, Yiyang 413000, Peoples R China.
关键词：
tunnel engineering;various ground shaking;dynamic response;axial force;bending moment
摘要：
The axial force and bending moment of tunnel lining are crucial for lining stability. To investigate the response patterns of axial force and bending moment in shallow-buried biased small clearance tunnels under various conditions-including different adjacent slope angles, loading wave types, peak loads, and loading directions-extensive numerical simulations were conducted. The numerical results were subsequently verified through large-scale vibration table physical model experiments. The findings reveal that the variation patterns of lining axial force and bending moment under bidirectional coupled seismic waves demonstrate similarity to those under vertical seismic waves. Vertical seismic motion exerts a more pronounced influence on lining axial force response. Seismic wave peak intensity significantly affects lining axial force and bending moment, with both parameters showing gradual increases corresponding to peak load escalation. The arch shoulder of the slope-side right tunnel lining exhibits particularly strong axial force and bending moment responses. While Darui wave, Wenchuan wave, and Kobe wave produce essentially consistent axial force and bending moment response patterns in tunnel linings, their magnitudes differ substantially. Seismic wave type primarily influences response magnitude rather than characteristic patterns of axial force distribution. Increasing slope angles adjacent to tunnels correlate with heightened axial force and bending moment responses in linings. A logarithmic functional relationship exists between slope angle and response values at the lining arch shoulder. These findings provide valuable references for seismic design of shallow-buried biased small clearance tunnels.
作者机构：
[Wu, Kuan; Li, Shouyi; Wang, Feifei] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;[Zhang, Huijie] China Coal Res Inst, Mine Safety Technol Branch, Beijing 100013, Peoples R China.;[Li, Bo; You, Bo; Chen, Yong] Hunan Univ Sci & Technol, Coll Resources Environm & Safety Engn, Xiangtan 411100, Peoples R China.;[Ma, Heyi] Hunan Coal Sci Res Inst Co Ltd, Changsha 410000, Peoples R China.;[Chen, Yong] China Coal Sci & Ind Grp Co LTD, Chongqing Res Inst, Chongqing 400037, Peoples R China.
通讯机构：
[Wu, K ] H;Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.
摘要：
To study the initial characteristics of gas desorption in high-rank soft and hard coals, a purpose-built constant-temperature gas desorption device was used to conduct gas desorption experiments on three groups of collected high-rank soft and hard coal samples. The results show that the gas desorption index (K (1)) of drill cuttings from soft and hard coals follows a power function relationship with the adsorption equilibrium pressure. Under the same adsorption equilibrium pressure, the gas desorption index (K (1)) of drill cuttings from soft coal is 1.39-2.66 times that of hard coal. When the adsorption equilibrium pressure is 1 MPa, in the first 1 min, the gas desorption rate of soft coal is 1.38-2.56 times that of hard coal, and in the first 10 min, the gas desorption rate of soft coal is 1.35-2.49 times that of hard coal. The initial law of gas desorption in soft and hard coals is suitable for classifying Sun Zhongxu's form of the governing equation. To reveal the causes of the differences in the initial characteristics of high-rank soft and hard coal gas desorption from a microscopic perspective, scanning electron microscopy (SEM) was used to observe the surface pore structure of soft and hard coals. Additionally, mercury intrusion porosimetry (MIP) and low-temperature N(2) adsorption/desorption (LTN(2)GA) experiments were undertaken to ascertain the full pore size distribution of soft and hard coal samples. The results show that (1) the breccia pores on the surface of soft coal are more developed, and the pore connectivity is better, which provides favorable conditions for the rapid desorption of gas at the initial stage. Furthermore, the crushed grain pores and ink bottle pores on the surface of soft coal are more developed, providing a place for the adsorption of more gas; (2) the total pore capacity of soft coal is 4.12-10.57 times that of hard coal, and the proportion of large and medium pore capacity in soft coal is 4.47-10.70 times that of hard coal, which provides a favorable channel for the rapid desorption of gas in the initial stage. The ratio of medium and micropore specific surface area of soft coal is 2.26-2.77 times that of hard coal, offering more positions for gas adsorption. The results offer a reference for those seeking to understand the differences in gas desorption in the early stage of high-rank soft and hard coals and provide technical support for improving the accuracy of determining coalbed gas content and gas desorption index (K (1)) of drill cuttings.
作者：
Dan Zhang*;Lei Zhang;Yonglin Gao;Xinzhong Wang;Yukui Wang
期刊：
Construction and Building Materials,2025年491:142609 ISSN：0950-0618
通讯作者：
Dan Zhang
作者机构：
[Dan Zhang; Lei Zhang; Xinzhong Wang; Yukui Wang] College of Civil Engineering, Hunan City University, No.518 Yingbindong Road, Yiyang 413000, China;[Yonglin Gao] Faculty of Architecture and City Planning, Kunming University of Science and Technology, No. 727 Jingming South Road, Kunmin 650500, China
通讯机构：
[Dan Zhang] C;College of Civil Engineering, Hunan City University, No.518 Yingbindong Road, Yiyang 413000, China
摘要：
External beam-column joints are generally recognized as critical components in ductile steel frame structures. The incorporation of minimally invasive and easily replaceable knee braces offers an effective retrofitting solution. This study investigates the feasibility of enhancing the seismic behavior of external beam-column joints in steel structures through the utilization of knee braces. The mechanical behavior of knee-braced retrofitted joints was analyzed to derive expressions for internal forces in the beam, column, and joint connection components. By utilizing principles of force balance and deformation compatibility between the beam, column, and joint components, a shear coefficient expression was formulated to quantify the knee brace’s impact on the internal forces within the beam and column. Furthermore, methods were developed to calculate the bending and shear capacities of the joint, as well as the axial capacity of the knee brace. The failure modes and sequences of the joint were predicted using a strength hierarchy evaluation method, and the validity of this approach was confirmed through experimental data from both retrofitted and non-retrofitted joints. Finally, the impact of critical design parameters, such as horizontal projection length, installation angle, and section type of the knee brace, on the strength hierarchy and failure modes of external steel frame joints was examined, providing valuable insights for the design of knee-braced retrofitted joints.
External beam-column joints are generally recognized as critical components in ductile steel frame structures. The incorporation of minimally invasive and easily replaceable knee braces offers an effective retrofitting solution. This study investigates the feasibility of enhancing the seismic behavior of external beam-column joints in steel structures through the utilization of knee braces. The mechanical behavior of knee-braced retrofitted joints was analyzed to derive expressions for internal forces in the beam, column, and joint connection components. By utilizing principles of force balance and deformation compatibility between the beam, column, and joint components, a shear coefficient expression was formulated to quantify the knee brace’s impact on the internal forces within the beam and column. Furthermore, methods were developed to calculate the bending and shear capacities of the joint, as well as the axial capacity of the knee brace. The failure modes and sequences of the joint were predicted using a strength hierarchy evaluation method, and the validity of this approach was confirmed through experimental data from both retrofitted and non-retrofitted joints. Finally, the impact of critical design parameters, such as horizontal projection length, installation angle, and section type of the knee brace, on the strength hierarchy and failure modes of external steel frame joints was examined, providing valuable insights for the design of knee-braced retrofitted joints.
期刊：
Measurement Science And Technology,2025年36(4):046133 ISSN：0957-0233
通讯作者：
Zhang, S
作者机构：
[Zhang, Sheng] Hunan City Univ, Sch Management, Yiyang 413000, Hunan, Peoples R China.;[Zhang, Liang; Huang, Ning; Zhang, Sheng; Deng, Zongwei] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Zhang, Liang; Zhang, Sheng; Deng, Zongwei] Hunan City Univ, Higher Educ Inst Hunan Prov, Key Lab Green Bldg & Intelligent Construct, Yiyang 413000, Hunan, Peoples R China.;[Chen, Qianqian] Hunan Commun Polytech, Inst Civil Engn, Changsha 410000, Hunan, Peoples R China.
通讯机构：
[Zhang, S ] H;Hunan City Univ, Sch Management, Yiyang 413000, Hunan, Peoples R China.;Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;Hunan City Univ, Higher Educ Inst Hunan Prov, Key Lab Green Bldg & Intelligent Construct, Yiyang 413000, Hunan, Peoples R China.
关键词：
rock classification;wavelet scattering transform;support vector machine;sensitivity analysis;deep learning
摘要：
In geological exploration and tunnel/underground engineering, precise, rapid, and intelligent rock lithology identification is crucial. A wavelet scattering transform-support vector machine (WST-SVM) rock image classification method is proposed that combines WST with SVM to address the limitations of conventional convolutional neural networks reliant on annotated samples. The method extracts multi-scale features from rock images using WST and trains an SVM classifier, achieving superior performance in test accuracy, macro-average precision, recall, and F1-score on a dataset of six rock types. Parameter analysis reveals that increasing invariant scale, decomposition transformations, and quality factor enhances feature matrix dimensionality and computational time. This approach reduces the need for extensive annotated samples and provides a practical solution for improving the accuracy and efficiency of rock lithology identification in geological exploration and tunnel engineering.
摘要：
The shear failure of concrete is a sudden brittle failure, which is difficult to be forewarned. To investigate the shear crack mechanisms in concrete, this study first systematic compared acoustic emission (AE) behavior during direct shear tests, compression shear tests (Z-shaped specimens), and three point bending shear tests. AE parameters (amplitude, cumulative count and energy), average frequency (AF)-rise time/amplitude (RA) analysis, K-means clustering, and b-value analysis were integrated to classify cracks and characterize damage progression. The correlation between the shear crack propagation mechanism of concrete and AE parameters was revealed. The AE activity during concrete shear failure was successfully characterized, providing valuable insights into the damage development and evolution processes. The research findings establish a quantitative framework for using AE technology to detect shear cracks and monitor real-time damage evolution in concrete structures.
摘要：
The existence of multiple cracks accelerates chloride ion penetration within damaged concrete, substantially shortening the lifespan of the structure. Therefore, this paper conducts an in-depth analysis of chloride migration mechanisms in cracked concrete subjected to multiple cracks under drying-wetting cycles. Firstly, a series of accelerated chloride diffusion experiments were conducted on prestressed concrete beams subjected to multiple cracks. The analysis examines how crack width, depth, and density affect chloride concentration distribution. Then, a chloride diffusion coefficient prediction model incorporating the effects of multiple cracks was established using the crack interaction function and verified through experimental data. Finally, this paper explored the distribution patterns of chloride concentration and convection zones in concrete subjected to multiple cracks under various environmental conditions. The experimental results showed that crack width exerts the strongest effect on chloride diffusion, followed by crack depth, while crack density has the smallest impact. At the same depth of diffusion, the chloride concentration in concrete specimens with crack width of 0.3 mm increased by 45 % and 25 % on average compared with those with crack width of 0.1 mm and 0.2 mm, respectively. The dry-wet time ratio and initial moisture saturation significantly affect chloride concentration distribution, with the depth of the convection zone showing a negative correlation with initial moisture saturation.
The existence of multiple cracks accelerates chloride ion penetration within damaged concrete, substantially shortening the lifespan of the structure. Therefore, this paper conducts an in-depth analysis of chloride migration mechanisms in cracked concrete subjected to multiple cracks under drying-wetting cycles. Firstly, a series of accelerated chloride diffusion experiments were conducted on prestressed concrete beams subjected to multiple cracks. The analysis examines how crack width, depth, and density affect chloride concentration distribution. Then, a chloride diffusion coefficient prediction model incorporating the effects of multiple cracks was established using the crack interaction function and verified through experimental data. Finally, this paper explored the distribution patterns of chloride concentration and convection zones in concrete subjected to multiple cracks under various environmental conditions. The experimental results showed that crack width exerts the strongest effect on chloride diffusion, followed by crack depth, while crack density has the smallest impact. At the same depth of diffusion, the chloride concentration in concrete specimens with crack width of 0.3 mm increased by 45 % and 25 % on average compared with those with crack width of 0.1 mm and 0.2 mm, respectively. The dry-wet time ratio and initial moisture saturation significantly affect chloride concentration distribution, with the depth of the convection zone showing a negative correlation with initial moisture saturation.
摘要：
Gas adsorption characteristics of coal seams are primarily controlled by the pore structure of coal. To clarify the pore structure and adsorption characteristics of soft and hard coal, this paper experimentally studied Jiulishan anthracite, Shanxi Xinyuan lean coal, and Panbei gas-fat coal. Combined with FHH, Langmuir, and Polanyi theories, pore structures and adsorption properties of soft/hard coals with varying metamorphism were analyzed. Results show that hard coal exhibited more developed macropores but fewer micro/mesopores than soft coal. Higher metamorphism increased maximum mercury intrusion volume and total pore volume. Hard coal mercury curves with varying metamorphism show negligible/small hysteresis loops and semi-closed pores. Soft coal exhibits hysteresis loops dominated by semi-closed and “ink-bottle” pores. Pore fractal dimensions exhibit a two-stage pattern, with each stage fractal dimension increasing with metamorphism and damage. As coal rank increases, adsorption constant a rises from 25.84 to 37.59 cm 3 /g, while b fluctuates between 0.76 and 1.54 MPa −1 . Soft coals of the same rank show higher saturated adsorption capacities than hard coals. All adsorption curves display polynomial behavior, with adsorption potential energy increasing with metamorphism and soft coal having greater surface adsorption potential energy than hard coal.
期刊：
Journal of Pipeline Systems Engineering and Practice,2025年16(3):03125001 ISSN：1949-1190
通讯作者：
Hu, D
作者机构：
[Qi, Kai; Yang, Xian; Liang, Xiaoqiang; Hu, Da; Li, Yongsuo; Hu, D] Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, 518 Yingbin East Rd, Yiyang 413000, Peoples R China.;[Xiang, Xuejuan; Qi, Kai; Huang, Junjie] Hunan City Univ, Sch Civil Engn, 518 Yingbin East Rd, Yiyang 413000, Peoples R China.
通讯机构：
[Hu, D ] H;Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, 518 Yingbin East Rd, Yiyang 413000, Peoples R China.
关键词：
Rectangular top pipe tunnel;Experimental analysis method;Empirical formula method;Numerical simulation method;Theoretical analysis method
摘要：
The jacking force in the construction process of rectangular pipe jacking tunnels is characterized by its intermittent, discontinuous, and unstable nature. This force not only determines the speed of tunneling but also controls the rate at which soil stress is released, leading to deformation of the formation and land subsidence, thereby impacting the surrounding environment. To accurately calculate and predict the jacking force of rectangular pipe jacking tunnels, this study conducts a comprehensive investigation and analysis of relevant literature on the calculation methods employed both domestically and internationally. The calculation methods are categorized into four types: experimental analysis methods, numerical simulation methods, theoretical formula methods, and empirical formula methods. The research content of each of these methods is analyzed and organized, and the existing research is summarized in terms of its problems and shortcomings. Furthermore, suggestions for future research on the calculation method of the jacking force are proposed, aiming to provide a technical reference for the theoretical research and engineering practice of calculating and predicting the jacking force of rectangular pipe jacking tunnels.
期刊：
Journal of Mining Science,2025年61(1):71-79 ISSN：1062-7391
通讯作者：
Wang, FF
作者机构：
[Wang, Feifei] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;[Wang, Feifei] Hunan City Univ, Key Lab Green Bldg & Intelligent Construct Higher, Yiyang 413000, Peoples R China.
通讯机构：
[Wang, FF ] H;Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;Hunan City Univ, Key Lab Green Bldg & Intelligent Construct Higher, Yiyang 413000, Peoples R China.
关键词：
mining engineering;underground goaf;high-cold and high-altitude;landslide and collapse;disaster formation mechanism
摘要：
In order to study the formation mechanism of the high-cold and high-altitude mountain collapse disaster caused by underlying complex goaf group, the lithology, occurrence of structural planes in rock mass and hydrological conditions of overburden in goaf were obtained through field investigation. Combined with the field investigation results, the landslide disaster mechanism was comprehensively analyzed. The stability of the mountain slope in the underlying goaf and the potential slip arc surface of the collapse body are analyzed by the two-dimensional finite element analysis method. The main causes of surface collapse of mountain slope are: the steep structural plane of rock mass, rainfall and fissure water erosion, freeze-thaw cycle, underground ore body mining disturbance, etc. Geological conditions are the internal cause, while underground mining is the inducement. The combined action of the internal and external causes leads to the special formation mechanism of collapse.
作者：
Zhang, Liang;Jiang, Hao;Zhang, Sheng;Bei, Zhenghao;Huang, Ning
期刊：
Measurement,2025年253:117561 ISSN：0263-2241
通讯作者：
Jiang, H
作者机构：
[Zhang, Liang; Huang, Ning; Zhang, Sheng] Hunan City Univ, Coll Civil Engn, 518 Yingbin East Rd, Yiyang 413000, Hunan, Peoples R China.;[Bei, Zhenghao; Jiang, Hao] Changsha Univ Sci & Technol, Sch Civil Engn, 960 Wanjiali South RD, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Jiang, H ] C;Changsha Univ Sci & Technol, Sch Civil Engn, 960 Wanjiali South RD, Changsha 410114, Hunan, Peoples R China.
关键词：
Tunnel lining detection;Cavity filler;Forward simulation;Generalized S -transform;Wavelet packet analysis
摘要：
Tunnel lining cavities and other defects can cause cracks in tunnel structures and damage to concrete, seriously affecting the safety of driving in tunnels. Due to varying geological conditions, the materials filling different cavity areas in tunnels differ. By formulating corresponding repair measures for different fillers in cavity areas, many unnecessary losses can be avoided. Therefore, this paper proposes a method based on multi-parameter information for identifying and extracting the characteristics of different fillers in tunnel cavity areas through forward simulation using gprMax software and field test analysis. Ground penetrating radar (GPR) is used to detect cavities of different shapes filled with various media, focusing on cavity signals while reducing interference from I-beams, and reconstructing radar signals through migration. Statistical parameters are introduced for analysis, and techniques such as Fast Fourier Transform, generalized S-transform, and wavelet packet transform are employed to extract features from the processed radar signals. The characteristics of the filling medium in the cavity area are extracted from three aspects: frequency, time–frequency, and energy. This method can provide a reference for interpreting the GPR data of tunnel lining cavity filling media in actual engineering applications.
Tunnel lining cavities and other defects can cause cracks in tunnel structures and damage to concrete, seriously affecting the safety of driving in tunnels. Due to varying geological conditions, the materials filling different cavity areas in tunnels differ. By formulating corresponding repair measures for different fillers in cavity areas, many unnecessary losses can be avoided. Therefore, this paper proposes a method based on multi-parameter information for identifying and extracting the characteristics of different fillers in tunnel cavity areas through forward simulation using gprMax software and field test analysis. Ground penetrating radar (GPR) is used to detect cavities of different shapes filled with various media, focusing on cavity signals while reducing interference from I-beams, and reconstructing radar signals through migration. Statistical parameters are introduced for analysis, and techniques such as Fast Fourier Transform, generalized S-transform, and wavelet packet transform are employed to extract features from the processed radar signals. The characteristics of the filling medium in the cavity area are extracted from three aspects: frequency, time–frequency, and energy. This method can provide a reference for interpreting the GPR data of tunnel lining cavity filling media in actual engineering applications.
摘要：
Refrigeration technology provides a new method for preventing coal and gas protrusions. In this study, the freeze-thaw characteristics of gas-containing coal under various moisture conditions (0%–20%) were investigated through experiments conducted on an independently constructed freeze-thaw simulation platform for gas-containing coal. The results mainly include: 1) The cooling curves of externally watered coal samples exhibit four stages: rapid cooling, constant phase change, slow cooling and final constant temperature. The dry coal samples showed only rapid cooling, followed by temperature stabilization. 2) Freezing deformation occurred only when the moisture content exceeded 8%, and a “hysteresis” effect appeared in its temperature and deformation. 3) Under the same humidity conditions, the gas-containing coals produced significantly greater freezing strain than the non-gas-containing coals. The duration of the freeze-up deformation increases linearly with the increase in moisture content; the duration of the gas-containing coal is longer. 4) The residual strain after freeze-up is in a logarithmic function relationship with the moisture content. The freezing and expansion forces destroyed the pore structure, connecting medium-sized pores into large pores, and simultaneously generated new micropores, resulting in a significant increase in the proportion of large pores. These results indicate that moisture, temperature, and gas presence synergistically control the freeze-up deformation characteristics of coal, providing important insights into the application of freezing technology to coal and the intrinsic mechanisms of gas outbreak prevention.
期刊：
Advances in Civil Engineering,2025年2025(1):5594233 ISSN：1687-8094
通讯作者：
Zongwei Deng
作者机构：
[Jun Xiong; Qing Chen] Yiyang Traffic Planning , Survey and Design Institute Co., Ltd. , Yiyang , 413000 , China;[Lianghao Hu] School of Civil Engineering , University of South China , Hengyang , 421001 , China , usc.edu.cn;[Zongwei Deng] School of Civil Engineering , Hunan City University , Yiyang , 413000 , China , hncu.net
通讯机构：
[Zongwei Deng] S;School of Civil Engineering , Hunan City University , Yiyang , 413000 , China , hncu.net
摘要：
To enhance the engineering properties of granite residual soil for subgrade filling, cement is incorporated to improve the soil. Through compaction tests, direct shear tests, and scanning electron microscope (SEM) tests, the influence of adding different doses of cement on the shear strength, residual strength, and microstructure of granite residual soil is investigated. The experimental results show that the maximum dry density increases and the optimal moisture content decreases with increasing cement content up to 7%. The shear strength is significantly enhanced with the increase in cement content. This effect is mainly attributed to the significant improvement in soil cohesion due to the addition of cement. When the cement content exceeds 7%, the shear strength index still increases with the cement content, but the rate of change slows down significantly. The failure mode of improved soil exhibits brittle failure, with residual strength remaining unchanged after cement content reaches 3%. At lower stress levels, the residual strength of the improved soil is similar to the shear strength of the undisturbed granite residual soil; while at higher stress levels, the residual strength of the improved soil is inferior to the shear strength of the undisturbed granite residual soil. SEM images reveal that cement hydration products gradually fill pores, forming a continuous spatial network structure. Considering both effectiveness and economic factors, the optimal cement content is approximately 5%. These findings contribute to a deeper understanding of the engineering properties of cement-improved granite residual soil and provide guidance for related engineering construction.
期刊：
Journal of Constructional Steel Research,2025年235:109872 ISSN：0143-974X
通讯作者：
Jianxin Peng
作者机构：
College of Civil and Construction Engineering, Hunan Institute of Technology, Hengyang, Hunan 421002, China;[Jianxin Peng] School of Civil Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China;[Yiming Yang] School of Civil Engineering, Hunan City University, Yiyang, Hunan 413000, China;[Yan Yao] Guangzhou Branch of China Road and Bridge Corporation, Guangzhou, Guangdong 510000, China;[Yi Liu] College of Civil and Construction Engineering, Hunan Institute of Technology, Hengyang, Hunan 421002, China<&wdkj&>School of Civil Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China
通讯机构：
[Jianxin Peng] S;School of Civil Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China
摘要：
Weld residual stress (WRS) is a major contributor to fatigue cracking at the U-rib-to-deck (RD) joints of orthotropic steel bridge decks (OSBD). To investigate the generation, and distribution mechanism of WRS and its impact on the ultimate bearing capacity, an FEA model of the RD joint was developed by using a thermo-mechanical coupling calculation approach. Then, the differences in WRS of RD joints with different weld forms were compared. Furthermore, a simulation method considering WRS for the ultimate bearing capacity of OSBD and a theoretical formula for its calculation were developed. Finally, the impact of different weld types on the RD joint's ultimate bearing capacity was compared. The results revealed that the maximum WRS values at the weld center were 410 MPa, which highlights the need for particular attention to fatigue failure at this location. For the application of different weld forms in RD joints, it is recommended to prioritize concave welds for structures with high fatigue requirements, while convex welds are more suitable for non-critical areas with low fatigue requirements, and select right-angle welds in regions of moderate fatigue requirements. The ultimate bearing capacity considering WRS showed a 5 % improvement in accuracy compared to that without WRS. The ultimate bearing capacity of the RD joint can be calculated by using the theoretical formula proposed in this article. Additionally, the weld type has a negligible consequence on the ultimate bearing capacity of OSBD.
Weld residual stress (WRS) is a major contributor to fatigue cracking at the U-rib-to-deck (RD) joints of orthotropic steel bridge decks (OSBD). To investigate the generation, and distribution mechanism of WRS and its impact on the ultimate bearing capacity, an FEA model of the RD joint was developed by using a thermo-mechanical coupling calculation approach. Then, the differences in WRS of RD joints with different weld forms were compared. Furthermore, a simulation method considering WRS for the ultimate bearing capacity of OSBD and a theoretical formula for its calculation were developed. Finally, the impact of different weld types on the RD joint's ultimate bearing capacity was compared. The results revealed that the maximum WRS values at the weld center were 410 MPa, which highlights the need for particular attention to fatigue failure at this location. For the application of different weld forms in RD joints, it is recommended to prioritize concave welds for structures with high fatigue requirements, while convex welds are more suitable for non-critical areas with low fatigue requirements, and select right-angle welds in regions of moderate fatigue requirements. The ultimate bearing capacity considering WRS showed a 5 % improvement in accuracy compared to that without WRS. The ultimate bearing capacity of the RD joint can be calculated by using the theoretical formula proposed in this article. Additionally, the weld type has a negligible consequence on the ultimate bearing capacity of OSBD.
摘要：
During shield tunnel construction, karst development along the tunnel axis and in the surrounding area frequently poses a significant threat to engineering safety. To address this challenge, this study proposes multiple grouting systems and systematically analyzes the key mechanical properties of five grout formulations through orthogonal experiments, identifying the optimal formulations for engineering applications. A predictive model was established using linear regression, and its accuracy was validated through independent single-factor experiments. The results indicate the following: (1) Water content is the primary factor influencing fluidity, with its significance varying by system composition. The lake mud-cement grout exhibits the highest compressive pstrength. Moderate sand addition enhances strength, but excessive amounts significantly reduce fluidity. Additives demonstrate system dependency: HY-4 effectively improves fluidity, while sodium silicate significantly increases strength but reduces fluidity. (2) The developed model demonstrates good goodness of fit, with coefficients of determination (R(2)) ranging from 0.74 to 0.95, without significant autocorrelation or multicollinearity. Validation experiments confirm the model's high predictive accuracy, with overall trends consistent with the measured data. (3) The lake mud-cement grout (A3B1C3) is recommended for reinforcement projects prioritizing stability, achieving a 28-day compressive strength of 4.74 MPa. The on-site wet clay-cement grout (A2B3C1) is suitable for high-permeability formations, with a strength of 1.1 MPa and a fluidity of 292.5 mm, both exceeding standard requirements. The findings provide optimized formulations and theoretical references for grouting reinforcement in karst tunnel projects.
作者机构：
[Cheng, Xiaokang; Xiao, Junyi; Peng, Jianxin; Zhang, Jianren] Changsha Univ Sci & Technol, Sch Civil Engn, Key Lab Bridge Engn Safety Control, Dept Educ, Changsha 410114, Hunan, Peoples R China.;[Xiao, Junyi] Guangzhou Vocat Coll Technol & Business, Sch Emergency Technol, Guangzhou 511442, Guangdong, Peoples R China.;[Yang, Yiming] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Dong, You] Hong Kong Polytech Univ, Dept Civil & Environm Engn, Hong Kong 999077, Peoples R China.
通讯机构：
[Peng, JX ] C;[Yang, YM ] H;Changsha Univ Sci & Technol, Sch Civil Engn, Key Lab Bridge Engn Safety Control, Dept Educ, Changsha 410114, Hunan, Peoples R China.;Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.
关键词：
Post-tensioned concrete structures;Chloride wet-dry environment;Performance degradation;Concrete creep;Prestress loss
摘要：
The shrinkage, creep of concrete, and relaxation of prestressing tendons lead to prestress loss in prestressed concrete (PC) structures under conventional environments. The prestress loss of PC structures is also affected by corrosive environments resulting from alternating wet and dry. Therefore, a new model for predicting prestress loss under alternating damp and dry chloride environments is proposed. The model considers the coupled effects of corrosion on concrete creep and the remaining cross-sectional area of steel reinforcement/prestressing tendons. A 300-day experimental study is conducted on a series of post-tensioned prestressed concrete beams subjected to a cyclic wet-dry corrosive environment to discuss prestress loss. The effectiveness of the model is verified through experimental results. The results indicate that the existing codes underestimate the long-term prestress loss of PC structures in corrosive environments. The proposed model can accurately predict the long-term prestress loss of PC beams. Compared with conventional environments, the creep coefficient of concrete under a dry-wet alternating corrosive environment increases by 15 %, resulting in a 12.4 % increase in the long-term prestress loss of the structure.
The shrinkage, creep of concrete, and relaxation of prestressing tendons lead to prestress loss in prestressed concrete (PC) structures under conventional environments. The prestress loss of PC structures is also affected by corrosive environments resulting from alternating wet and dry. Therefore, a new model for predicting prestress loss under alternating damp and dry chloride environments is proposed. The model considers the coupled effects of corrosion on concrete creep and the remaining cross-sectional area of steel reinforcement/prestressing tendons. A 300-day experimental study is conducted on a series of post-tensioned prestressed concrete beams subjected to a cyclic wet-dry corrosive environment to discuss prestress loss. The effectiveness of the model is verified through experimental results. The results indicate that the existing codes underestimate the long-term prestress loss of PC structures in corrosive environments. The proposed model can accurately predict the long-term prestress loss of PC beams. Compared with conventional environments, the creep coefficient of concrete under a dry-wet alternating corrosive environment increases by 15 %, resulting in a 12.4 % increase in the long-term prestress loss of the structure.
期刊：
International Journal for Numerical and Analytical Methods in Geomechanics,2025年 ISSN：0363-9061
通讯作者：
Ni, PP
作者机构：
[Liu, Jing; Liang, Xiaoqiang; Hu, Da; Li, Yongsuo] Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, Yiyang, Peoples R China.;[Xiang, Xuejuan; Liu, Jing; Liang, Xiaoqiang; Huang, Junjie; Hu, Da; Li, Yongsuo] Hunan City Univ, Sch Civil Engn, Yiyang, Peoples R China.;[Ni, Pengpeng; Ni, PP] Sun Yat sen Univ, Sch Civil Engn, State Key Lab Tunnel Engn, Guangzhou, Peoples R China.;[Ni, Pengpeng; Ni, PP] Southern Marine Sci & Engn Guangdong Lab Zhuhai, Zhuhai, Peoples R China.
通讯机构：
[Ni, PP ] S;Sun Yat sen Univ, Sch Civil Engn, State Key Lab Tunnel Engn, Guangzhou, Peoples R China.;Southern Marine Sci & Engn Guangdong Lab Zhuhai, Zhuhai, Peoples R China.
关键词：
box jacking tunnel;jacking force;soil arching effect;stress transfer
摘要：
During the construction of box jacking tunnel, stress transfer caused by the soil arching effect is an important factor, affecting the jacking force. This study proposes a jacking force prediction method for box jacking tunnels under the complete and incomplete soil arching effect in sandy soils, which is divided into three soil domains, i.e., an external stable region, an elastic arch, and an internal loosened body. Three-dimensional numerical analyses for box jacking tunnel at various cover depths are also investigated to show the stress changes in the soil around the tunnel and the evolution of soil arch formation. Finally, through theoretical derivation and case analysis, the ratio between the influence range of soil arching and the width of loosened soil, f 0 / f 0 f 1 f 1 ${{{f_0}} \mathord{/ {\vphantom {{{f_0}} {{f_1}}}} \kern-\nulldelimiterspace} {{f_1}}}$ , is found to increase with increasing the tunnel size and internal friction angle of soil. The f 0 / f 0 f 1 f 1 ${{{f_0}} \mathord{/ {\vphantom {{{f_0}} {{f_1}}}} \kern-\nulldelimiterspace} {{f_1}}}$ coefficient can be preliminarily determined to be approximately 1.4, with a marginal difference of 6.7% compared with the Terzaghi's proposal of 1.5. Results show that in sandy and silty soil strata, the proposed method outperforms the other methods, in terms of accuracy and adaptability. This study can serve as a theoretical reference for the design and construction of box jacking tunnels.
期刊：
JOURNAL OF COMPUTING IN CIVIL ENGINEERING,2025年39(3):04025017 ISSN：0887-3801
通讯作者：
Hu, D
作者机构：
[Hu, Da; Li, Yongsuo; Hu, D] Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, 518 Yingbin East Rd, Yiyang 413000, Peoples R China.;[Weng, Xiaoxuan; Tan, Ze; Liu, Jing] Hunan City Univ, Coll Civil Engn, Yingbin East Rd, Yiyang 413000, Hunan, Peoples R China.;[Qi, Kai] Univ South China, Coll Civil Engn, Henyang 421001, Hunan, Peoples R China.
通讯机构：
[Hu, D ] H;Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, 518 Yingbin East Rd, Yiyang 413000, Peoples R China.
关键词：
Prediction of jacking force;Pipe jacking tunnel;Deep-learning;Convolutional neural network;Long-term and short-term memory network
摘要：
The advancement of computer technology has led to the increased utilization of new algorithms, such as machine learning, in various fields including underground engineering. The estimation of jacking force plays a critical role in the construction of rectangular jacked tunnels. Conventional prediction techniques often rely on empirical models and statistical analysis, posing challenges in accurately forecasting the jacking force for intricate tunnel structures. To overcome this obstacle, a method for predicting tunnel jacking force is proposed, which integrates a convolutional neural network (CNN) and long short-term memory network (LSTM). By utilizing geometric and operational parameters as inputs, the CNN extracts data features, which are subsequently inputted into the LSTM network for time-series modeling. This model effectively processes continuous jacking force data by comprehending the complex correlations within the data set, resulting in more precise predictions of future jacking force values. Comparative analysis with traditional methods such as the artificial neural network, single CNN model, and LSTM network demonstrates that the CNN-LSTM model significantly reduces prediction errors in tunnel jacking force estimation, thereby enhancing model accuracy. Consequently, the efficacy of the CNN-LSTM model has been validated, showcasing the benefits of employing deep-learning techniques for predicting jacking force in pipe jacking tunnel construction.
摘要：
Surface collapse pits caused by intense mining activities in underground mines have long been a research focus and challenging issue in the field of geological hazards. To investigate the characteristics and formation mechanisms of surface collapse disasters, field investigations were conducted to determine the morphological characteristics, spatial extent, and depth profiles of collapse pits, Based on a typical case of surface subsidence in a mine, the PFC2D discrete element numerical simulation was employed to reconstruct the complete failure process from overburden rock collapse to surface subsidence. This study elucidates the formation and evolution processes of surface collapse pits from three perspectives: fracture evolution, displacement variation, and force chain distribution. Results demonstrate that the eastern, southern, and western rock masses exhibit two distinct failure modes: tensile fracture-collapse and tensile fracture-tilting, forming characteristic steep-walled pit features. Partial shear failure cracks develop at both extremities of the fracture zones. In contrast, the northern section primarily fails through tensile fracture-sliding, creating step-like landslide features. The current settlement feature presents an elliptical shape with a size of 275 m (north–south) × 210 m (east–west). The overburden rock failure predominantly manifests tensile cracking, with upward-propagating fractures emerging at both ends of the goaf—indicative of progressive roof collapse. The maximum 5690 fractures were generated in the rock mass. As mining depth increases, overlying rock displacement above the ore body escalates dramatically. The overburden develops an architectural pattern featuring a large pressure arch encompassing multiple localized smaller pressure arches, with concentrated force chains forming along the goaf flanks. The collapse pit formation process comprises four distinct stages: disaster initiation, rock deformation, structural collapse, and pit stabilization. This study provides a theoretical basis for the prevention and control of surface collapse disaster in mines.
期刊：
Desalination and Water Treatment,2025年322:101161 ISSN：1944-3994
通讯作者：
Li, ZP
作者机构：
[Yin, Quan; Zhou, Yi; Li, Zhiping] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.;[Yin, Quan; Zhou, Yi; Li, Zhiping] Hunan City Univ, Hunan Engn Res Ctr Struct Safety & Disaster Preven, Yiyang 413000, Peoples R China.;[Ma, Lidong] Sinohydro Engn Bur 8 Co Ltd, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li, ZP ] H;Hunan City Univ, Sch Civil Engn, Yiyang 413000, Peoples R China.
关键词：
Magnetic amino-functionalized biochar;Hexavalent chromium;Removal performance;Potential mechanisms
摘要：
Magnetic amino-functionalized sludge biochar (Fe@NBC) was prepared via a one-step method for efficient Cr(VI) removal from tailing wastewater. Static adsorption research was conducted to investigate the impacts of solution pH, coexisting ion, reaction times, pollutant concentrations, and reaction temperature on removing Cr(VI) from tailing wastewater. Spectroscopic analysis was used to research the removal mechanisms of Cr(VI). Compared with the original sludge biochar, Fe@NBC exhibited a more developed pore structure and richer reactive sites. Adsorption experiments showed that Fe@NBC achieved higher adsorption and reduction rates of Cr(VI) than BC, with faster reaction equilibrium time. The efficiencies of removing Cr(VI) on Fe@NBC decreased with increasing solution pH. The efficiencies of removing Cr(VI) by Fe@NBC decreased with increasing SO 4 2- concentration, while Cl - and NO - 3 held almost no impact on removing Cr(VI). The process of removing Cr(VI) by Fe@NBC followed pseudo-second-order kinetic model and Langmuir model. Thermodynamics suggested that Cr(VI) removal on Fe@NBC was a spontaneous and endothermic processes. The main mechanisms for Cr(VI) removal by Fe@NBC were coordination and reduction, while pore filling and electrostatic interactions played secondary roles. This work demonstrated that Fe@NBC, a magnetic amino-functionalized sludge biochar, was a highly efficient and environmentally friendly material for removing Cr(VI) from tailing wastewater.
Magnetic amino-functionalized sludge biochar (Fe@NBC) was prepared via a one-step method for efficient Cr(VI) removal from tailing wastewater. Static adsorption research was conducted to investigate the impacts of solution pH, coexisting ion, reaction times, pollutant concentrations, and reaction temperature on removing Cr(VI) from tailing wastewater. Spectroscopic analysis was used to research the removal mechanisms of Cr(VI). Compared with the original sludge biochar, Fe@NBC exhibited a more developed pore structure and richer reactive sites. Adsorption experiments showed that Fe@NBC achieved higher adsorption and reduction rates of Cr(VI) than BC, with faster reaction equilibrium time. The efficiencies of removing Cr(VI) on Fe@NBC decreased with increasing solution pH. The efficiencies of removing Cr(VI) by Fe@NBC decreased with increasing SO 4 2- concentration, while Cl - and NO - 3 held almost no impact on removing Cr(VI). The process of removing Cr(VI) by Fe@NBC followed pseudo-second-order kinetic model and Langmuir model. Thermodynamics suggested that Cr(VI) removal on Fe@NBC was a spontaneous and endothermic processes. The main mechanisms for Cr(VI) removal by Fe@NBC were coordination and reduction, while pore filling and electrostatic interactions played secondary roles. This work demonstrated that Fe@NBC, a magnetic amino-functionalized sludge biochar, was a highly efficient and environmentally friendly material for removing Cr(VI) from tailing wastewater.
