管棚注浆支护隧道开挖引起地表变形特征分析

隧道开挖引起的地表变形是工程安全的重要指标,基于管棚注浆隧道开挖引起的地层受力分析,将地表变形影响因素分为注浆压力、附加荷载和地层损失,并引入Mindlin解和Peck公式,获得了隧道引起的地表变形计算公式.通过对地表变形特征进行分析,结果表明:岩土力学参数对地表变形最大值有显著影响,但对沉降影响宽度影响甚微;沉降槽宽...

The Characteristic Analysis of Ground Deformation due to Tunnel Excavation Used Pipe Roof Grouting Support System

Ground deformation caused by tunnel excavation is an important index of engineering safety. Based on the stress analysis caused by the excavation of tunnel under the grouting with pipe-roof, the main influence factors of ground deformation are divided into grouting pressure, additional load and ground loss. And the formula of calculating the ground deformation has been presented by introducing the Mindlin solution and Peck formula. The characteristic of ground deformation has been studied, and the research results reveal that mechanics parameters of rock and soil mass have significant effect on the maximum ground settlement but little effect on the width of settlement (I). The width of settlement trough (i), ground loss rate (η) and I/i decrease with the increase of friction angle and cohesion. The value of i is 7.6~7.9 and is not affected by the elastic modulus. With the increase of elastic modulus, the value of η decreases rapidly and stabilizes around 1.2‰, but the value of I/i increases rapidly and stabilizes around 3.0. Different from the mechanics parameters of rock and soil mass, the tunnel parameters have significant effect on the maximum ground settlement and the width of settlement (I), and the influence amplitude does not decrease. With the increase of tunnel depth in the single layered foundation, the value of i and η is increase as a linear, but the value of I/i is increases at first then decreases. With the increase of tunnel diameter, the value of i increases as a linear and the value of η decreases as a linear, but the value of I/i increases at first then decreases and its maximum value is around 3.1.