【摘要】 以广深港客运专线狮子洋水下盾构隧道为背景工程,采用轴向等效刚度模型,开展盾构隧道单、双层衬砌纵向力学性能模型试验,并结合数值模拟计算,研究在软硬交替地层且地表有局部附加荷载的复杂情况下,单、双层衬砌隧道纵向沉降与弯矩的变化规律。结果表明:隧道处于软硬交界地层中时,单层衬砌的纵向沉降受地层条件的变化作用明显,较大的沉降量和沉降差均发生在软土侧;双层衬砌可在一定程度上抵御受地层条件的变化作用而产生的不均匀沉降,隧道纵向中心最大沉降量和沉降差均较小;管片衬砌内侧施加连续的混凝土内衬后,隧道所受纵向弯矩成倍增大,最大正弯矩出现在隧道中央偏向软土侧,且混凝土内衬承受绝大部分弯矩;当荷载距隧道轴线3倍洞径以内时,会对隧道的纵向变形及内力产生影响。更多还原

【Abstract】 Taking Shiziyang underwater shield tunnel of Guangzhou-Shenzhen-Hongkong passenger dedicated line as engineering background,model tests on the longitudinal mechanical properties of single and double layered linings were conducted using equivalent axial stiffness model.Combined with numerical calculations,the variations of longitudinal settlement and bending moment of shield tunnels with single and double layered linings under the junction of hard and soft strata in the conditions that the surface upon the tunnel is partially loaded were studied.Results show that the longitudinal settlement of single-layered lining is significantly influenced by the change of strata when the tunnel is located at the junction of hard and soft strata.Both larger settlement and differential settlement occur on the side of soft strata.Double-layered lining can resist uneven settlement caused by the change of strata to some extent.Both the maximum settlement and differential settlement at the longitudinal center of tunnel are smaller.After concrete lining is continuously applied to the inner side of segment lining,the longitudinal bending moment of tunnel is doubled,and the maximum positive bending moment occurs slightly at the soft strata side of the tunnel center.Most bending moment is borne by concrete lining.When the load is located within three times of tunnel diameter from tunnel axis,the longitudinal deformation and internal force of tunnel will be affected.更多还原