Xiaopu Cui , Pengfei Li , Yang Chen , Fei Jia , Zhaoguo Ge , Shaohua Li
{"title":"Analysis of face stability for a shield tunnel in the inclined strata with soft upper and hard lower layers","authors":"Xiaopu Cui , Pengfei Li , Yang Chen , Fei Jia , Zhaoguo Ge , Shaohua Li","doi":"10.1016/j.aej.2025.04.013","DOIUrl":null,"url":null,"abstract":"<div><div>Tunnel excavation often encounters inclined strata with a soft upper layer and a hard lower layer at the excavation face. Currently, limited research has been conducted on the mechanisms underlying the instability of such strata. This paper proposes a new excavation face failure mechanism considering the inclination angle and soil arching effect, and classify the failure models into two types according to the inclination angle. The results of numerical simulations and existing theories are used to validate our model. Through sensitivity analysis of soil strength parameters, the analytical results indicate that as the inclination angle changes from counterclockwise to clockwise, the limit support pressure first decreases, then increases, and then gradually decreases. The internal friction angle of the inclined strata significantly affects the limit support pressure. The influence of cohesion difference on the limit support pressure gradually weakens. Under clockwise inclination angles, the limit support pressure mainly depends on the strength parameters of the upper layer. This paper provides a more accurate theoretical basis for the stability analysis of shield tunnels in inclined strata with soft upper and hard lower layers, which is of great significance for guiding the design and construction of shield tunnels in complex geological conditions.</div></div>","PeriodicalId":7484,"journal":{"name":"alexandria engineering journal","volume":"125 ","pages":"Pages 677-691"},"PeriodicalIF":6.2000,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"alexandria engineering journal","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1110016825004806","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Tunnel excavation often encounters inclined strata with a soft upper layer and a hard lower layer at the excavation face. Currently, limited research has been conducted on the mechanisms underlying the instability of such strata. This paper proposes a new excavation face failure mechanism considering the inclination angle and soil arching effect, and classify the failure models into two types according to the inclination angle. The results of numerical simulations and existing theories are used to validate our model. Through sensitivity analysis of soil strength parameters, the analytical results indicate that as the inclination angle changes from counterclockwise to clockwise, the limit support pressure first decreases, then increases, and then gradually decreases. The internal friction angle of the inclined strata significantly affects the limit support pressure. The influence of cohesion difference on the limit support pressure gradually weakens. Under clockwise inclination angles, the limit support pressure mainly depends on the strength parameters of the upper layer. This paper provides a more accurate theoretical basis for the stability analysis of shield tunnels in inclined strata with soft upper and hard lower layers, which is of great significance for guiding the design and construction of shield tunnels in complex geological conditions.
期刊介绍:
Alexandria Engineering Journal is an international journal devoted to publishing high quality papers in the field of engineering and applied science. Alexandria Engineering Journal is cited in the Engineering Information Services (EIS) and the Chemical Abstracts (CA). The papers published in Alexandria Engineering Journal are grouped into five sections, according to the following classification:
• Mechanical, Production, Marine and Textile Engineering
• Electrical Engineering, Computer Science and Nuclear Engineering
• Civil and Architecture Engineering
• Chemical Engineering and Applied Sciences
• Environmental Engineering