Underground Space最新文献

{"title":"Prediction of fracture initiation in cohesive soils based on data mining modelling and large-scale laboratory verification","authors":"","doi":"10.1016/j.undsp.2024.01.007","DOIUrl":"10.1016/j.undsp.2024.01.007","url":null,"abstract":"<div><p>Many empirical and analytical methods have been proposed to predict fracturing pressure in cohesive soils. Most of them take into account three to four specific influencing factors and rely on the assumption of a failure mode. In this study, a novel data-mining approach based on the XGBoost algorithm is investigated for predicting fracture initiation in cohesive soils. This has the advantage of handling multiple influencing factors simultaneously, without pre-determining a failure mode. A dataset of 416 samples consisting of 14 distinct features was herein collected from past studies, and used for developing a regressor and a classifier model for fracturing pressure prediction and failure mode classification respectively. The results show that the intrinsic characteristics of the soil govern the failure mode while the fracturing pressure is more sensitive to the stress state. The XGBoost-based model was also tested against conventional approaches, as well as a similar machine learning algorithm namely random forest model. Additionally, several large-scale triaxial fracturing tests and an in-situ case study were carried out to further verify the generalization ability and applicability of the proposed data mining approach, and the results indicate a superior performance of the XGBoost model.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 279-300"},"PeriodicalIF":8.2,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000503/pdfft?md5=1186b98abc7e5d3abbd8dd10fd0ac771&pid=1-s2.0-S2467967424000503-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141034726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"Dongming Zhang","doi":"10.1016/j.undsp.2024.04.002","DOIUrl":"https://doi.org/10.1016/j.undsp.2024.04.002","url":null,"abstract":"","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 4-5"},"PeriodicalIF":6.4,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000485/pdfft?md5=3666d9df991026caa548e21a5d4e989a&pid=1-s2.0-S2467967424000485-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141428813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to the first Jeme Tien Yow Lecture","authors":"Hehua Zhu","doi":"10.1016/j.undsp.2024.04.001","DOIUrl":"https://doi.org/10.1016/j.undsp.2024.04.001","url":null,"abstract":"","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"18 ","pages":"Pages 1-2"},"PeriodicalIF":6.4,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000473/pdfft?md5=db634661c325d435105f4e62e806e0d3&pid=1-s2.0-S2467967424000473-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140906754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil conditioning of clay based on interface adhesion mechanism: Microscopic simulation and laboratory experiment","authors":"Yong Fang,&nbsp;Bin Zhuo,&nbsp;Ruyue Zhang,&nbsp;Yubo Wang,&nbsp;Liupan Dou,&nbsp;Yuxiang Yao","doi":"10.1016/j.undsp.2023.12.007","DOIUrl":"https://doi.org/10.1016/j.undsp.2023.12.007","url":null,"abstract":"<div><p>Clogging frequently occurs in the cutter head, excavation chamber or screw conveyor when an earth pressure balance (EPB) shield machine is tunneling in soft or silty clay ground with high clay mineral content. In this paper, montmorillonite, kaolinite, and illite were selected as research objects, and molecular dynamics (MD) simulation and laboratory experiment were adopted. At the microscopic scale, dynamic contact behavior and interfacial mechanical behavior of the interface between clay minerals and water/surfactant solution was simulated and the interfacial adhesion and conditioning mechanism between clay minerals and water/surfactant solution was revealed. Thus, sodium dodecyl benzene sulfonate (SDBS) surfactant was selected as the main composition of the soil conditioner. Then, the adhesion stress before and after soil conditioning and the contact angles between clay minerals and water/surfactant solution were tested and analyzed at the macroscopic scale. The result shows that the contact angle between droplet and clay mineral surface is an important parameter to characterize soil adhesion. The simulation rules of the microscopic contact angle are consistent with the experiment results. Furthermore, the adsorption energy between microscopic substances is dominated by electrostatic force, which can reflect the adhesion stress between macroscopic substances. Soil adhesion stress can be effectively decreased by adding the surfactant to the soil conditioner.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"18 ","pages":"Pages 239-255"},"PeriodicalIF":6.4,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000461/pdfft?md5=67caadaba449500a75f0cfe6586321b7&pid=1-s2.0-S2467967424000461-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141263856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Migration time prediction and assessment of toxic fumes under forced ventilation in underground mines","authors":"Jinrui Zhang ,&nbsp;Tingting Zhang ,&nbsp;Chuanqi Li","doi":"10.1016/j.undsp.2024.01.004","DOIUrl":"https://doi.org/10.1016/j.undsp.2024.01.004","url":null,"abstract":"<div><p>This study aims to predict the migration time of toxic fumes induced by excavation blasting in underground mines. To reduce numerical simulation time and optimize ventilation design, several back propagation neural network (BPNN) models optimized by honey badger algorithm (HBA) with four chaos mapping (CM) functions (i.e., Chebyshev (Che) map, Circle (Cir) map, Logistic (Log) map, and Piecewise (Pie) map) are developed to predict the migration time. 125 simulations by the computational fluid dynamics (CFD) method are used to train and test the developed models. The determination coefficient (<em>R</em>²), the variance accounted for (VAF), the Willmott’s index (WI), the root mean square error (RMSE), the mean absolute percentage error (MAPE), and the sum of squares error (SSE) are utilized to evaluate the model performance. The evaluation results indicate that the CirHBA-BPNN model has achieved the most satisfactory performance by reaching the highest values of <em>R</em>² (0.9945), WI (0.9986), VAF (99.4811%), and the lowest values of RMSE (15.7600), MAPE (0.0343) and SSE (6209.4), respectively. The wind velocity in roadway (<em>W</em>_v) is the most important feature for predicting the migration time of toxic fumes. Furthermore, the intrinsic response characteristic of the optimal model is implemented to enhance the model interpretability and provide reference for the relationship between features and migration time of toxic fumes in ventilation design.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"18 ","pages":"Pages 273-294"},"PeriodicalIF":6.4,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000448/pdfft?md5=fdbe69eadbfc36a8f4bfb03ecbe3f1db&pid=1-s2.0-S2467967424000448-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141286403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical model regarding compression-bending capacity of segmental joint reinforced by steel plate","authors":"Zhen Li ,&nbsp;Xuezeng Liu","doi":"10.1016/j.undsp.2024.01.005","DOIUrl":"10.1016/j.undsp.2024.01.005","url":null,"abstract":"<div><div>The mechanical properties of the steel-plate-reinforced segmental lining are generally determined by the load-bearing capacity of reinforced joints. However, there is a lack of valid calculation methods for compression-bending bearing capacity, and researchers mainly rely on experience and analogy for the design of reinforced joints. This paper proposes an analytical model based on the deformation and stress characteristics of the joint surface to calculate the compression-bending capacity of the steel-plate-reinforced joint. After verifying the applicability of this analytical model through finite element simulations, the evalution rules of the load-bearing capacity of the reinforced joint were attained, followed by a quantitative investigation into the influence of joint parameters on it. The results show that: (1) the bearing capacity curve of the reinforced joint under different axial forces can be separated into two parts, with the maximum ultimate bending moment found at the demarcation point, where the steel plate yielding and joint failure occur simultaneously; (2) the steel plate strength and cross-sectional area have a strong influence on the bearing capacity of the reinforced joint when the axial force is under 0.15RFF, where RFF is the axial force at pure-compression failure); (3) the concrete strength and segment width have a prominent influence on the curve when the axial force is over 0.30RFF; (4) the impact of the fictitious strain, bolt strength, bolt diameter, and bolt location on the bearing capacity is minimal in range and amplitude.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"20 ","pages":"Pages 157-173"},"PeriodicalIF":8.2,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disc-cutter induced rock breakage mechanism for TBM excavation in rock masses with different joint shear strengths","authors":"Bolong Liu ,&nbsp;Bo Li ,&nbsp;Liang Zhang ,&nbsp;Rui Huang ,&nbsp;Huicai Gao ,&nbsp;Shilin Luo ,&nbsp;Tao Wang","doi":"10.1016/j.undsp.2023.12.006","DOIUrl":"10.1016/j.undsp.2023.12.006","url":null,"abstract":"<div><p>When tunnel boring machines (TBMs) excavate through jointed rock masses, the cutting efficiency is strongly affected by the shear strength of joints, the mechanism of which, however, remains poorly understood. In this study, a series of disc-cutter indentation tests were conducted on granite rock mass specimens with different joint shear strengths. During the indentation, the cracking process was recorded by a digital image correlation (DIC) system. The deformation and strength of specimens, cracking behavior, rock breakage mode and cutting efficiency were quantitatively investigated. In addition, to investigate the combined effects of joint shear strength, orientation and spacing on the rock breakage mechanism, numerical rock mass models were established based on a particle flow code PFC2D. Experimental results reveal that the cracking of primary and secondary cracks changes from the mixed shear-tensile to tensile mode in the initial stage, while the joint shear strength does not affect the cracking mode in the subsequent propagation process. The rock breakage mode is classified to an internal block breakage mode, a cross-joint breakage mode and a cutters-dependent breakage mode. The cross-joint breakage mode is optimal for improving the cutting efficiency. Numerical simulation results reveal that the increase in the joint shear strength changes the internal block breakage mode to cross-joint breakage mode for rock masses of particular ranges of joint orientation and spacing. These findings provide basis for improving the TBM cutting efficiency through jointed rock masses.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 119-137"},"PeriodicalIF":8.2,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000436/pdfft?md5=dbf65fcbce77b037e7679c24b5051bf6&pid=1-s2.0-S2467967424000436-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140790426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MCS-based quantile value approach for reliability-based design of tunnel face support pressure","authors":"Bin Li,&nbsp;Changxing Wang,&nbsp;Hong Li","doi":"10.1016/j.undsp.2024.01.003","DOIUrl":"10.1016/j.undsp.2024.01.003","url":null,"abstract":"<div><p>This paper develops a new approach for reliability-based design (RBD) of tunnel face support pressure from a quantile value perspective. A surrogate model is constructed to calculate the collapse pressures of the random samples generated by a single run of Monte Carlo simulation (MCS). The cumulative distribution function (CDF) of the collapse pressure is then obtained and the support pressure aiming at a target failure probability is chosen as the upper quantile value of the collapse pressures. The proposed approach does not require repetitive reliability analyses compared to the existing methods. Moreover, a direct relationship between the target failure probability and the required support pressure is established. An illustrative example is used to demonstrate the implementation procedure. The accuracy of the reliability-based support pressures is verified by direct MCS incorporating with three-dimensional numerical simulations. Finally, the influencing factors, including the sample size of MCS, the correlation coefficient between random variables, the choice of experimental points, and the surrogate model, are investigated. This method can play a complementary role to available approaches due to its advantages of simplicity and efficiency.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"18 ","pages":"Pages 187-198"},"PeriodicalIF":6.4,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000424/pdfft?md5=cce4e3a8da26ece1e85330c1360abb86&pid=1-s2.0-S2467967424000424-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140785579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial for Machine learning and AI for underground metaverse","authors":"Kok-Kwang Phoon,&nbsp;Qiujing Pan,&nbsp;Chong Tang","doi":"10.1016/j.undsp.2024.03.002","DOIUrl":"10.1016/j.undsp.2024.03.002","url":null,"abstract":"","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 1-3"},"PeriodicalIF":6.4,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000412/pdfft?md5=a5e02d0792c31b0709d89572fb9e5c10&pid=1-s2.0-S2467967424000412-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140787017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance and environmental impacts of deep foundation excavation in soft soils: A field and modeling-based case study in Nanjing, China","authors":"Chenhe Ge ,&nbsp;Meng Yang ,&nbsp;Pengfei Li ,&nbsp;Mingju Zhang ,&nbsp;Zhonghao Zhang","doi":"10.1016/j.undsp.2024.01.002","DOIUrl":"10.1016/j.undsp.2024.01.002","url":null,"abstract":"<div><p>This paper focuses on the performance of a braced deep excavation in soft soil based on field monitoring and numerical modeling. Laboratory tests were conducted to determine the soil parameters used in the modified Cam–Clay (MCC) model. Intelligent field monitoring means were adopted and a three-dimensional model was established. Spatial and temporal effects induced by the excavation are investigated for the deep-large foundation pit in soft soil. Deformation characteristics of the enclosure structure and the surrounding environment throughout the excavation process are presented. The behaviors of diaphragm walls, columns, the maximum wall deflection rate, ground surface settlement, and utility pipelines were focused on and investigated during the whole excavation process. Besides, the axial forces of the internal supports are analyzed. Based on the measured and simulated data, the following main conclusions were obtained: the numerical simulation results are in good agreement with the measured values, which proves the accuracy of the model parameters; the wall and the ground surface showed the maximum displacement increment at stage 9, which was a coupled product of the “creep effect” of the soft soil in Nanjing, China and the “depth effect” of the excavation; as the excavation progressed, the ground settlement changed from a “rising” to a “spoon-shaped” trend, <em>δ</em>_vm was measured between <em>δ</em>_vm = 0.0686%<em>H</em> and <em>δ</em>_vm = 0.1488%<em>H</em>; the rebound deformation curve of the pit bottom was corrugated, and the depth of disturbance of the pit bottom after the completion of soil unloading was 2–3 times the excavation depth; the closer the pipeline is to the corner of the pit, the less the excavation process will affect the settlement of the pipeline and the less the obvious pit corner effect will occur; the support strength of the buttress and the longest corner brace should be strengthened during the actual construction process to ensure the stability of the foundation deformation.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"18 ","pages":"Pages 218-238"},"PeriodicalIF":6.4,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000321/pdfft?md5=c6f5bd122f50852365862fdb3606c53d&pid=1-s2.0-S2467967424000321-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140789190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}