微风化砂岩盾构近距离下穿既有盾构隧道力学响应分析  

NUMERICAL SIMULATION ANALYSIS OF DEFORMATION OF EXISTING SHIELD TUNNELING IN SLIGHTLY WEATHERED SANDSTONE UNDER PASSED BY SHIELD TUNNELING IN SHORT DISTANCE

作　　者：徐武 赵顺磊 XU Wu;ZHAO Shun-lei(CCCC Second Highway Engineering Co.,Ltd.,710054,Xi'an,China)

机构地区：[1]中交第二公路工程局有限公司,西安710054

出　　处：《建筑技术》2024年第9期1050-1054,共5页Architecture Technology

摘　　要：依托广州地铁12号线二沙岛站至岭南广场站区间盾构工程,综合工程地质资料、设计参数及既有盾构隧道结构特点进行分析,通过开展系列三维模拟分析,系统研究微风化砂岩盾构隧道下穿施工对既有地铁盾构隧道结构所造成的不利影响,探究地铁隧道在不同程度的刚度折减后受到的影响,评估既有盾构隧道结构的安全性。研究表明,新建隧道下穿引起的既有盾构隧道椭变增量形式均为竖椭变,并随着盾构隧道的刚度增加而减小;新建隧道下穿主要引起既有隧道结构及轨道的竖向位移,并随既有盾构隧道自身刚度减小而增大;新建隧道下穿后,既有隧道沿纵向表现出典型W形沉降槽趋势;既有盾构隧道的位移、弯矩变化值较小,并随着盾构隧道的刚度增加而减小。Based on the shield construction project between Ersha Island Station and Lingnan Square Station of Guangzhou Metro Line 12,the paper comprehensively analyses the engineering geological data,design parameters and structural characteristics of existing shield tunnels,and systematically studies the adverse effects of slightly weathered sandstone shield tunneling crossing on the existing subway shield tunnel structure by carrying out a series of three-dimensional simulation analysis.To explore the impact of different degree of stiffness reduction on the subway tunnel and evaluate the safety of existing shield tunnel structure.The research shows that the ellipsoidal increments of existing shield tunnels are all vertical ellipsoidal and decrease with the increase of stiffness of shield tunnels.The underpass of the new tunnel mainly causes the vertical displacement of the existing tunnel structure and track,and the displacement increases with the decrease of the stiffness of the existing shield tunnel.After the new tunnel passes through,the existing tunnel shows a typical W-shaped settlement trough trend along the longitudinal direction.The displacement and bending moment of existing shield tunnels change slightly,and decrease with the increase of stiffness of shield tunnels.

关 键 词：微风化砂岩 盾构隧道 近距离下穿 力学响应 数值模拟 

分 类 号：TU43[建筑科学—岩土工程]