Tao Zhang , Yufeng Shi , Shuying Wang , Menghao Hu , Sijin He
{"title":"上软下硬地层盾构隧道衬砌作用荷载及力学特性研究","authors":"Tao Zhang , Yufeng Shi , Shuying Wang , Menghao Hu , Sijin He","doi":"10.1016/j.sandf.2025.101647","DOIUrl":null,"url":null,"abstract":"<div><div>When shield tunnels traverse the upper-soft and lower-hard stratum, the pronounced geological differences lead to uneven stress distribution on the segmental lining, thereby intensifying both construction challenges and safety risks. Investigating the loading conditions and mechanical characteristics of tunnel linings in such strata is imperative. Therefore, field measurements were conducted at two shield tunnel construction sites along Nanchang Metro Line 1, specifically within a silty clay-gravel layer and a homogeneous sand layer. The acting load and internal forces of the segmental lining were monitored over an extended period. By analyzing the monitoring data, the variation patterns of the loads acting on the segmental lining in the upper-soft and lower-hard stratum during the construction stage were summarized. Furthermore, a comparative analysis was carried out between the measured loading conditions and the theoretical analytical solutions. Subsequently, a refined numerical simulation incorporating bolt joints and bolt preload on the segment was performed to further explore the mechanical behavior of the segmental lining, with a comparison to the measured internal force data. The results indicate that synchronous grouting at the shield tail significantly affects the earth pressure in the upper soft soil layer, with the maximum earth pressure induced by synchronous grouting being approximately 1.9 times the final stable value. The vertical earth pressure in the upper part of the segmental lining exhibits a characteristic pattern of being “large in the middle and small at both ends”, with the measured maximum value after stabilization corresponding to approximately 72% of the theoretical value predicted by Terzaghi’s theory. Notably, a sudden change in lateral earth pressure is observed at the stratum interface. The bending moment and axial force at the invert of the tunnel segment are comparatively smaller than those at the vault. Additionally, the development of internal forces within the segment is fairly constrained in the lower hard stratum.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101647"},"PeriodicalIF":3.3000,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Investigation of acting load and mechanical characteristics of shield tunnel lining in upper-soft and lower-hard stratum\",\"authors\":\"Tao Zhang , Yufeng Shi , Shuying Wang , Menghao Hu , Sijin He\",\"doi\":\"10.1016/j.sandf.2025.101647\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>When shield tunnels traverse the upper-soft and lower-hard stratum, the pronounced geological differences lead to uneven stress distribution on the segmental lining, thereby intensifying both construction challenges and safety risks. Investigating the loading conditions and mechanical characteristics of tunnel linings in such strata is imperative. Therefore, field measurements were conducted at two shield tunnel construction sites along Nanchang Metro Line 1, specifically within a silty clay-gravel layer and a homogeneous sand layer. The acting load and internal forces of the segmental lining were monitored over an extended period. By analyzing the monitoring data, the variation patterns of the loads acting on the segmental lining in the upper-soft and lower-hard stratum during the construction stage were summarized. Furthermore, a comparative analysis was carried out between the measured loading conditions and the theoretical analytical solutions. Subsequently, a refined numerical simulation incorporating bolt joints and bolt preload on the segment was performed to further explore the mechanical behavior of the segmental lining, with a comparison to the measured internal force data. The results indicate that synchronous grouting at the shield tail significantly affects the earth pressure in the upper soft soil layer, with the maximum earth pressure induced by synchronous grouting being approximately 1.9 times the final stable value. The vertical earth pressure in the upper part of the segmental lining exhibits a characteristic pattern of being “large in the middle and small at both ends”, with the measured maximum value after stabilization corresponding to approximately 72% of the theoretical value predicted by Terzaghi’s theory. Notably, a sudden change in lateral earth pressure is observed at the stratum interface. The bending moment and axial force at the invert of the tunnel segment are comparatively smaller than those at the vault. Additionally, the development of internal forces within the segment is fairly constrained in the lower hard stratum.</div></div>\",\"PeriodicalId\":21857,\"journal\":{\"name\":\"Soils and Foundations\",\"volume\":\"65 4\",\"pages\":\"Article 101647\"},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2025-06-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Soils and Foundations\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0038080625000812\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, GEOLOGICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Soils and Foundations","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0038080625000812","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
Investigation of acting load and mechanical characteristics of shield tunnel lining in upper-soft and lower-hard stratum
When shield tunnels traverse the upper-soft and lower-hard stratum, the pronounced geological differences lead to uneven stress distribution on the segmental lining, thereby intensifying both construction challenges and safety risks. Investigating the loading conditions and mechanical characteristics of tunnel linings in such strata is imperative. Therefore, field measurements were conducted at two shield tunnel construction sites along Nanchang Metro Line 1, specifically within a silty clay-gravel layer and a homogeneous sand layer. The acting load and internal forces of the segmental lining were monitored over an extended period. By analyzing the monitoring data, the variation patterns of the loads acting on the segmental lining in the upper-soft and lower-hard stratum during the construction stage were summarized. Furthermore, a comparative analysis was carried out between the measured loading conditions and the theoretical analytical solutions. Subsequently, a refined numerical simulation incorporating bolt joints and bolt preload on the segment was performed to further explore the mechanical behavior of the segmental lining, with a comparison to the measured internal force data. The results indicate that synchronous grouting at the shield tail significantly affects the earth pressure in the upper soft soil layer, with the maximum earth pressure induced by synchronous grouting being approximately 1.9 times the final stable value. The vertical earth pressure in the upper part of the segmental lining exhibits a characteristic pattern of being “large in the middle and small at both ends”, with the measured maximum value after stabilization corresponding to approximately 72% of the theoretical value predicted by Terzaghi’s theory. Notably, a sudden change in lateral earth pressure is observed at the stratum interface. The bending moment and axial force at the invert of the tunnel segment are comparatively smaller than those at the vault. Additionally, the development of internal forces within the segment is fairly constrained in the lower hard stratum.
期刊介绍:
Soils and Foundations is one of the leading journals in the field of soil mechanics and geotechnical engineering. It is the official journal of the Japanese Geotechnical Society (JGS)., The journal publishes a variety of original research paper, technical reports, technical notes, as well as the state-of-the-art reports upon invitation by the Editor, in the fields of soil and rock mechanics, geotechnical engineering, and environmental geotechnics. Since the publication of Volume 1, No.1 issue in June 1960, Soils and Foundations will celebrate the 60th anniversary in the year of 2020.
Soils and Foundations welcomes theoretical as well as practical work associated with the aforementioned field(s). Case studies that describe the original and interdisciplinary work applicable to geotechnical engineering are particularly encouraged. Discussions to each of the published articles are also welcomed in order to provide an avenue in which opinions of peers may be fed back or exchanged. In providing latest expertise on a specific topic, one issue out of six per year on average was allocated to include selected papers from the International Symposia which were held in Japan as well as overseas.