Underground Space最新文献

{"title":"Experimental study on shield tunnel seepage control via microbially induced calcite precipitation","authors":"Shuai Zhao ,&nbsp;Shi-Fan Wu ,&nbsp;Dong-Ming Zhang ,&nbsp;Hong-Wei Huang ,&nbsp;Jian Chu","doi":"10.1016/j.undsp.2024.03.007","DOIUrl":"10.1016/j.undsp.2024.03.007","url":null,"abstract":"<div><div>This study investigated the potential use of microbially induced calcite precipitation (MICP) to prevent seepage in shield tunnels with the aim of decarbonizing tunnel engineering. An apparatus was developed to conduct scale model tests to evaluate the effectiveness of using MICP for shield tunnel seepage control. To understand the MICP process and its induced change in seepage flow rate, a series of 1-<em>g</em> physical model tests were conducted using the designed apparatus to investigate the effect of injection methods, grouting pressure, and calcium carbonate (CaCO₃) content produced as well as its distribution on the reduction of seepage flow rate for thephysical tunnel model with different backfills behind its linings. The variation law of the pore pressure near grouting hole of the tunnel segment was also revealed. Results indicated that when the amount of CaCO₃ precipitation in sand-grout mixtures was 10.53% and 10.12%, water seepage flow rate for thephysical tunnel modelwith Fujian- and coarse-sand-grout backfill respectively reduced by 94.3% and 73.8% of their respective initial values, and S-wave velocity increased by 89.6% and 84.9% for Fujian- and coarse-sand-grout mixture, respectively. The grouting pressure needed to be controlled within a certain range to prevent the unstable CaCO₃ precipitates from being washed away. The testing results also showed that the one-phase injection method was more effective in controlling seepage water into a shield tunnel. Based on the findings of the scale model tests, some vital considerations and suggestions were presented on the use of MICP approaches for shield tunnel seepage control.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"21 ","pages":"Pages 65-80"},"PeriodicalIF":8.2,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141845501","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":"Integrated approach of predicting rock stability in high mountain valley underground caverns","authors":"Fuyuan Tan ,&nbsp;Haosen Guo ,&nbsp;Pengzhi Pan ,&nbsp;Zhaofeng Wang ,&nbsp;Xufeng Liu ,&nbsp;Yangyi Zhou","doi":"10.1016/j.undsp.2024.04.005","DOIUrl":"10.1016/j.undsp.2024.04.005","url":null,"abstract":"<div><p>High mountain valleys are characterized by the development of intricate ground stress fields due to geological processes such as tectonic stress, river erosion, and rock weathering. These processes introduce considerable stability concerns in the surrounding rock formations for underground engineering projects in these regions, highlighting the imperative need for rigorous stability assessments during the design phase to ensure construction safety. This paper introduces an innovative approach for the pre-evaluation of the stability of surrounding rocks in underground caverns situated within high mountain valleys. The methodology comprises several pivotal steps. Initially, we conduct inverse calculations of the ground stress field in complex geological terrains, combining field monitoring and numerical simulations. Subsequently, we ascertain stress-strength ratios of the surrounding rocks using various rock strength criteria. To assess the stability characteristics of the surrounding rocks in the 1^# spillway cave within our project area, we employ numerical simulations to compute stress-strength ratios based on different rock strength criteria. Furthermore, we undertake a comparative analysis, utilizing data from the 5^# Underground Laboratory (Lab 5) of Jinping II Hydropower Station, aligning the chosen rock strength criterion with the damage characteristics of Lab 5′s surrounding rocks. This analysis serves as the cornerstone for evaluating other mechanical responses of the surrounding rocks, thereby validating the pre-evaluation methodology. Our pre-evaluation method takes into account the intricate geological evolution processes specific to high mountain valleys. It also considers the influence of the initial geostress field within the geological range of underground caverns. This comprehensive approach provides a robust foundation for the analysis and assessment of the stability of surrounding rocks, especially in high mountain valley areas, during the design phase of underground engineering projects. The insights derived from this analysis hold substantial practical significance for the effective guidance of such projects.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 317-341"},"PeriodicalIF":8.2,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000746/pdfft?md5=0f212efa334d36d48b5f77f1824979d9&pid=1-s2.0-S2467967424000746-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141838869","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":"MatDEM-based study of disc cutter force model in open TBM tunnels: Incorporating installation radius and synergistic effects","authors":"Yadong Xue ,&nbsp;Lushan Shu ,&nbsp;Lan Zhao ,&nbsp;Wei Luo ,&nbsp;Yongfa Guo","doi":"10.1016/j.undsp.2024.02.008","DOIUrl":"10.1016/j.undsp.2024.02.008","url":null,"abstract":"<div><div>The prediction of rock cutting force is critical for tunnel boring machine performance and cutterhead design. This paper presents a novel model for rock cutting force prediction based on the Colorado School of Mines (CSM) model, which incorporates the installation position of disc cutters by introducing installation radius and synergistic effect factors. Linear cutting tests in the laboratory and large-scale rotary cutting simulations in MatDEM software were conducted to examine the impact of these factors. Results indicate that the normal and rolling forces increase and stabilize as the installation radius increases. The synergistic effect produces three force modes in a cutting circle, with mode α having the largest cutting force, mode β having a smaller force, and mode γ having the smallest force. The impact of installation radius and synergistic effect varies with rock-cutter parameters. Multiple regression analysis was used to determine the introduced factors. The proposed model was validated with rock strength and operation data from the Irtysh River conveyance project. The results demonstrate that the proposed model outperforms the CSM model in predicting cutting force in field conditions.</div></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"20 ","pages":"Pages 293-310"},"PeriodicalIF":8.2,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141852516","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":"Model test on cutterhead-soil interaction during shield tunneling and its theoretical model","authors":"Xiang Shen ,&nbsp;Dajun Yuan ,&nbsp;Dalong Jin ,&nbsp;Xiangsheng Chen ,&nbsp;Weiping Luo ,&nbsp;Yuansheng Peng ,&nbsp;Kai Duan","doi":"10.1016/j.undsp.2024.03.006","DOIUrl":"10.1016/j.undsp.2024.03.006","url":null,"abstract":"<div><p>This study aims to develop a rational theoretical model for cutterhead-soil interaction. The cutterhead-soil interaction mechanism is divided into two components: the cutting action of the cutter on the soil and the extrusion of the cutterhead on the soil. By enhancing the Mckyes–Ali model, we analyze and deduce the force state of the cutter during shield tunneling, obtaining a calculation method for determining the force on the cutter. Additionally, we conduct an in-depth analysis of the extrusion effect of the cutterhead on the soil during shield tunneling, utilizing the fundamental solution of the Kelvin problem. Based on these theoretical calculations, we validate the tunneling thrust and cutterhead torque of the shield using our self-developed multi-functional large-scale shield tunneling test platform. The test results demonstrate that the tunneling thrust and cutterhead torque derived from the established cutterhead-soil interaction model in this paper are relatively close to the experimental monitoring values. This provides a theoretical foundation for establishing reasonable shield tunneling loads.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"20 ","pages":"Pages 46-68"},"PeriodicalIF":8.2,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000722/pdfft?md5=6100098abc815e1895e44ae09c9c2df5&pid=1-s2.0-S2467967424000722-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141847383","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":"Vibration transfer from underground train to multi-story building: Modelling and validation with in-situ test data","authors":"Li Wang ,&nbsp;Xin Gao ,&nbsp;Caiyou Zhao ,&nbsp;Ping Wang ,&nbsp;Zili Li","doi":"10.1016/j.undsp.2024.04.004","DOIUrl":"10.1016/j.undsp.2024.04.004","url":null,"abstract":"<div><p>Excessive underground train-induced vibration becomes a serious environmental problem in cities. To investigate the vibration transfer from an underground train to a building nearby, an explicit-integration time-domain, three-dimensional finite element model is developed. The underground train, track, tunnel, soil layers and a typical multi-story building nearby are all fully coupled in this model. The complex geometries involving the track components and the building are all modelled in detail, which makes the simulation of vibration transfer more realistic from the underground train to the building. The model is validated with in-situ tests data and good agreements have been achieved between the numerical results and the experimental results both in time domain and frequency domain. The proposed model is applied to investigate the vibration transfer along the floors in the building and the influences of the soil stiffness on the vibration characteristics of the track-tunnel-soil-building system. It is found that the building vibration induced by an underground train is dominant at the frequency determined by the P2 resonance and influenced by the vibration modes of the building. The vertical vibration in the building decreases in a fluctuant pattern from the foundation to the top floor due to loss of high frequency contents and local modes. The vibration levels in different rooms at a same floor can be different due to the different local stiffness. A room with larger space thus smaller local stiffness usually has higher vibration level. Softer soil layers make the tunnel lining and the building have more low frequency vibration. The influence of the soil stiffness on the amplification scale along the floors of the building is found to be nonlinear and frequency-dependent, which needs to be further investigated.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 301-316"},"PeriodicalIF":8.2,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000710/pdfft?md5=d73516275ef4edd5f9166ea38a8c8160&pid=1-s2.0-S2467967424000710-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141696351","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":"Optimization of spatial layouts for underground facilities to achieve carbon neutrality in cities: A multi-agent system model","authors":"Lingxiang Wei ,&nbsp;Dongjun Guo ,&nbsp;Junyuan Ji ,&nbsp;Zhilong Chen ,&nbsp;Huapeng Hu ,&nbsp;Xiaoli Peng","doi":"10.1016/j.undsp.2024.03.005","DOIUrl":"https://doi.org/10.1016/j.undsp.2024.03.005","url":null,"abstract":"<div><p>Subways, underground logistics systems and underground parking, as the primary facilities types of underground, contribute significantly to the achievement of carbon–neutral cities by moving surface transportation to underground, thereby releasing surface space for the creation of more urban blue-green space for carbon sink. Therefore, in-depth studies on carbon neutrality strategies as well as reliable layout optimization solutions of these three types of underground facilities are required. This study proposes a spatial layout optimization strategy for carbon neutrality using underground hydrogen storage and geothermal energy for these three types of underground facilities employing a multi-agent system model. First, three spatial layout relationships, competition, coordination, and followership, between five underground facilities that contribute to emission reduction were investigated. Second, the implementation steps for optimizing the spatial layout of underground facilities were determined by defining the behavioral guidelines for spatial environment, underground facility, and synergistic agent. Finally, using the Tianfu New District in Chengdu City, China, as a case study, layouts of underground facilities under three different underground space development scenarios were simulated to verify the model. The findings of this study address the gap in the research on underground spatial facilities and their layout optimization in response to emission reduction. This study provided a significant reference for the study of underground space and underground resources at the planning level to aid in achieving carbon–neutral cities.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 251-278"},"PeriodicalIF":8.2,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S246796742400062X/pdfft?md5=6869e2d580c2e3bfac61c8356bb60278&pid=1-s2.0-S246796742400062X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141605096","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":"Permeability evolution of fluid-injection-reactivated granite fractures of contrasting roughnesses","authors":"Fengshou Zhang ,&nbsp;Guanpeng He ,&nbsp;Mengke An ,&nbsp;Rui Huang ,&nbsp;Derek Elsworth","doi":"10.1016/j.undsp.2024.02.007","DOIUrl":"10.1016/j.undsp.2024.02.007","url":null,"abstract":"<div><p>Fracture/fault instability induced by fluid injection in deep geothermal reservoirs could not only vary the reservoir permeability but also trigger hazardous seismicity. To address this, we conducted triaxial shear experiments on granite fractures with different architected roughnesses reactivated under fluid injection, to investigate the controls on permeability evolution linked to reactivation. Our results indicate that the fracture roughness and injection strategies are two main factors affecting permeability evolution. For fractures with different roughnesses, a rougher fracture leads to a lower peak reactivated permeability (<em>k</em>_max), and varying the fluid injection strategy (including the confining pressure and injection rate) has a less impact on <em>k</em>_max, indicating that the evolution of permeability during fluid pressurization is likely to be determined by the fracture roughness along the shear direction. Both the fracture roughness and injection strategies affect the average rates of permeability change and this parameter also reflects the long-term reservoir recovery. Our results have important implications for understanding the permeability evolution and the injection-induced fracture/fault slips in granite reservoirs during the deep geothermal energy extraction.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"20 ","pages":"Pages 33-45"},"PeriodicalIF":8.2,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000631/pdfft?md5=b8c7f8910f33c92161733ec946e116f2&pid=1-s2.0-S2467967424000631-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141716351","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":"Two-layer autonomous intelligence dynamic trajectory planning method based on shield-tunnel ring-geology interactions","authors":"Min Hu ,&nbsp;Bingjian Wu ,&nbsp;Huiming Wu ,&nbsp;Liefeng Pei","doi":"10.1016/j.undsp.2024.04.003","DOIUrl":"https://doi.org/10.1016/j.undsp.2024.04.003","url":null,"abstract":"<div><p>To solve the problem that current attitude planning methods do not fully consider the interaction and constraints among the shield, segmental tunnel ring, and geology, and cannot adapt to the changes in the actual engineering environment, or provide feasible long-term and short-term attitude planning, this paper proposes autonomous intelligent dynamic trajectory planning (AI-DTP) to provide tunnel ring and centimeter-layer planning targets for a self-driving shield to meet long-term accuracy and short-term rapidity. AI-DTP introduces the Frenet coordinate system to solve the problem of inconsistent spatial representation of tunnel data, segmental tunnel ring location, and surrounding geological conditions, designs the long short-term memory attitude prediction model to accurately predict shield attitude change trend based on shield, tunnel, and geology, and uses a heuristic algorithm for trajectory optimization. AI-DTP provides ring-layer and centimeter-layer planning objectives that meet the needs of long-term accuracy and short-term correction of shield attitude control. In the Hangzhou-Shaoxing Intercity Railroad Tunnel Project in China, the “Zhiyu” shield equipped with the AI-DTP system was faster and more accurate than the manually controlled shield, with a smoother process and better quality of the completed tunnel.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 227-250"},"PeriodicalIF":8.2,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000618/pdfft?md5=1c0b0b7e81a8deeb95dd203ddcd90bda&pid=1-s2.0-S2467967424000618-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141593230","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":"Experimental investigation on rockburst characteristics of highly stressed D-shape tunnel subjected to impact load","authors":"Wuxing Wu ,&nbsp;Fengqiang Gong ,&nbsp;Zongxian Zhang","doi":"10.1016/j.undsp.2024.02.006","DOIUrl":"https://doi.org/10.1016/j.undsp.2024.02.006","url":null,"abstract":"<div><p>Rockburst has always been a challenge for the safe construction of deep underground engineering. This study investigated the rockburst characteristics in highly-stressed D-shape tunnels under impact loads from rock blasting and other mining-related dynamics disturbances. The biaxial Hopkinson pressure bar was utilized to apply varying biaxial prestress and the same impact loads to cube specimens with D-shape hole. High-speed camera and digital image correlation (DIC) were used to capture the failure process and strain field of specimen. The test results demonstrate that the D-shape hole specimen experience rockburst under coupled static stress and impact load. Under this circumstance, the rockburst mechanism of the D-shaped hole specimens involves spalling in sidewall induced by impact load, indicating dynamic tensile failure. The high static prestress provides the initial stress field, while the impact load disrupts the stress equilibrium, result in the stress or strain concentration in the sidewall of the D-shape hole, inducing rockburst. Moreover, the rockburst process can be divided into (1) calm stage, (2) crack initiation, propagation, and coalesce stage, (3) spalling stage and (4) rock fragments ejection stage. Impact load triggers rockburst occurrence, while vertical stress further determines the rockburst characteristics. The influence range and magnitude of strain concentration zone and displacement deformation of the tunnel surrounding rock increases with increasing vertical stress, thus inducing more severe rockburst.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 153-168"},"PeriodicalIF":8.2,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467967424000606/pdfft?md5=c6e3288f9e4dfcd48cc57309977729d5&pid=1-s2.0-S2467967424000606-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141543087","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":"Novel stacking models based on SMOTE for the prediction of rockburst grades at four deep gold mines","authors":"Peng Xiao ,&nbsp;Zida Liu ,&nbsp;Guoyan Zhao ,&nbsp;Pengzhi Pan","doi":"10.1016/j.undsp.2024.03.004","DOIUrl":"10.1016/j.undsp.2024.03.004","url":null,"abstract":"<div><p>Rockburst is a frequently encountered hazard during the production of deep gold mines. Accurate prediction of rockburst is an important measure to prevent rockburst in gold mines. This study considers seven indicators to evaluate rockburst at four deep gold mines. Field research and rock tests were performed at two gold mines in China to collect these seven indicators and rockburst cases. The collected database was oversampled by the synthetic minority oversampling technique (SMOTE) to balance the categories of rockburst datasets. Stacking models combining tree-based models and logistic regression (LR) were established by the balanced database. Rockburst datasets from another two deep gold mines were implemented to verify the applicability of the predictive models. The stacking model combining extremely randomized trees and LR based on SMOTE (SMOTE-ERT-LR) was the best model, and it obtained a training accuracy of 100% and an evaluation accuracy of 100%. Moreover, model evaluation suggested that SMOTE can enhance the prediction performance for weak rockburst, thereby improving the overall performance. Finally, sensitivity analysis was performed for SMOTE-ERT-LR. The results indicated that the SMOTE-ERT-LR model can achieve satisfactory performance when only depth, maximum tangential stress index, and linear elastic energy index were available.</p></div>","PeriodicalId":48505,"journal":{"name":"Underground Space","volume":"19 ","pages":"Pages 169-188"},"PeriodicalIF":8.2,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S246796742400059X/pdfft?md5=f4000ba4a1acbe2637230419497d33f5&pid=1-s2.0-S246796742400059X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141410746","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}