摘要
为明确大断面隧道原位扩挖过程中不同扩挖时序对围岩收敛变形和应力重分布的力学响应特征,通过物理模型试验、数值模拟和工程实践相结合的方法,研究了传统中隔壁扩挖法与分台阶时序扩挖法对围岩收敛变形及应力重分布的影响,分析了分台阶时序扩挖法的围岩应力分布规律与位移变形特征。研究结果表明:分台阶时序扩挖法可有效控制围岩的位移量和应力释放率,并减弱传统中隔壁法对围岩应力突降和局部变形的影响;隧道拱脚具有应力集聚特征,左右拱脚集聚应力分别达4.2 MPa和4.6 MPa,超前支护可控制拱顶围岩的初期变形,但扩挖侧围岩表现出较大的位移变化,主要受二次扰动损伤影响;隧道扩挖过程中围岩应力和变形的模型试验值、数值模拟值与工程实测值具有较好的一致性,论证了分台阶时序扩挖法的有效性。研究结果为大断面隧道扩挖法优化和围岩稳定性控制提供了数据支撑和技术依据。
To clarify the mechanical response characteristics of surrounding rock convergence deformation and stress redistribution under different excavation sequences during the in-situ expansion of large-section tunnels,a research approach combining physical model tests,numerical simulations,and engineering practice was adopted.The effects of the traditional center diaphragm excavation method and the step-by-step sequential excavation method on surrounding rock convergence deformation and stress redistribution were investigated,and the stress distribution patterns and displacement deformation characteristics of the surrounding rock under the step-by-step sequential excavation method were analyzed.The research results indicate that the step-by-step sequential excavation method can effectively control the displacement and stress release rate of the surrounding rock,reducing the impact of sudden stress drops and localized deformation caused by the traditional center diaphragm method.Stress concentration characteristics were observed at the tunnel foot,with stress accumulation reaching 4.2 MPa and 4.6 MPa at the left and right tunnel foot,respectively.It was found that advanced support can control the initial deformation of the surrounding rock at the tunnel crown,whereas the sidewall rock mass on the excavation side exhibited significant displacement variations,primarily due to secondary disturbance-induced damage.The model test values,numerical simulation results,and field measurement data of surrounding rock stress and deformation during tunnel expansion were found to be in good agreement,verifying the effectiveness of the step-by-step sequential excavation method.The findings can provide data support and technical guidance for optimizing large-section tunnel excavation methods and controlling surrounding rock stability.
作者
王亮
赵英爱
宋子帆
刘志文
贾康
孙天翔
吕祥锋
WANG Liang;ZHAO Ying-ai;SONG Zi-fan;LIU Zhi-wen;JIA Kang;SUN Tian-xiang;L Xiang-feng(China Power Construction Road and Bridge Group Co.,Ltd.,Beijing 100160,China;China Power Construction(Guangdong)Zhongkai Expressway Co.,Ltd.,Jiangmen 529142,China;Key Laboratory of Ground Subsidence Mechanism and Prevention and Control of Hebei Province,Beijing University of Science and Technology,Beijing 100083,China)
出处
《科学技术与工程》
北大核心
2026年第1期277-288,共12页
Science Technology and Engineering
基金
国家自然科学基金面上项目(52278326)
国家高层次人才计划(SQ2022QB03353)
北京市杰出青年科学基金(JQ21028)
中电建路桥集团有限公司科技项目(LQKY2021-01)。
关键词
分台阶时序扩挖
大断面隧道
支护围岩
力学响应
试验研究
step-by-step sequential excavation
large-section tunnel
supported surrounding rock
mechanical response
experimental study
