考虑多因素的类矩形盾构施工引起土体竖向位移研究  

Deriving vertical displacement of ground due to quasi-rectangular shield tunneling considering multiple factors

作　　者：魏纲[1] 张鑫海 徐银锋 

机构地区：[1]浙江大学城市学院土木工程系,浙江杭州310015 [2]浙江大学建筑工程学院,浙江杭州310058

出　　处：《岩石力学与工程学报》2018年第1期199-208,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：浙江省科技厅公益技术研究项目(2016C33051);2017年度国家级大学生创新创业训练计划项目(201713021008);住房和城乡建设部2015年科学技术项目计划(2015–K5–026)~~

摘　　要：基于Mindlin位移解和随机介质理论,考虑正面附加推力、盾壳与土体之间的摩擦力、附加注浆压力和土体损失,研究类矩形盾构施工引起的土体竖向位移及各因素的影响。研究土体损失的过程中引入了开挖面收敛模式参数α和纵向损失率修正公式。研究结果表明:考虑多因素的土体竖向位移预测值与实测值较吻合,能反映出纵向地表沉降曲线在开挖面附近及后方地表出现隆起和沉降逐渐发展的过程;随着深度的增加土体沉降值增大;隧道轴线两侧的土体沉降增量要大于轴线正上方,沉降曲线呈W型。该方法也可以用于分析土仓压力不均的工况,此时开挖面前方的沉降曲线不再对称;正面附加压力减小,开挖面前方地表沉降值增加,反之,沉降值减小。Based on the Mindlin displacement solution and the stochastic medium theory, the vertical displacement of soil caused by the construction of the quasi-rectangular shield was derived considering the bulkhead additional thrust, the friction between the shield and the soil, the additional grouting pressure and the soil loss. A convergence mode coefficient a＇ at tunneling face and a revised formula of longitudinal loss rate were presented. The predicted vertical displacements agree with the measured values and reflect the process of uplift and gradual settlement of longitudinal settlement curve in the vicinity and at rear of the excavation front. The ground settlement increases with the depth. The soil settlement on two sides of the tunnel axis is larger than that above the axis and the settlement curve is W-shaped. The method proposed in this paper can also be used to analyze the cases that pressure of soil chamber is unequal. In such cases, the settlement curve in front of the excavation surface is no longer symmetrical. The bulkhead additive thrust decreases and the surface settlement increases in front of the excavation face.

关 键 词：土力学 类矩形盾构 多因素 土体竖向位移 开挖面收敛模式 随机介质理论 MINDLIN解 

分 类 号：TU43[建筑科学—岩土工程]