四渡河特大桥隧道式锚碇数值模拟

采用数值模拟方法研究了悬索桥隧道式锚碇系统的力学行为特征、围岩稳定状态、锚碇变位机理和拓扑效应。就锚碇体轴线倾角、长度、夹持角、接触界面粗糙度及结合程度对锚碇位移和岩体安息稳定性的影响作了深入探讨。研究发现:夹持角控制着锚碇变位和破坏机理,夹持角过小时锚碇压密围岩土体,较大时锚碇前端附近土体则产生剪切破坏;锚碇长度影响接触面围岩应力量值,表现为非线性的自组织临界特征;锚碇体粗细对系统主要监控参数的贡献相对均匀。给出了锚碇拓扑参数的取值范围和针对性的设计措施,为悬索桥隧道式锚碇的优化设计提供了理论基础。

Numerical Simulation on Tunnel Anchorage of Siduhe Super-Long Bridge

The mechanical behavior characteristics,stabilization state of surrounding rock,deformation mechanism of anchorage,topology effect of tunnel anchorage system of suspension bridge were studied based on numerical simulation method.Influences of axis inclination,length,clamping angle of anchorage,roughness and bonding degree of interface on the displacement of anchorage and repose stability of rock mass were explored.Results show that clamping angle dominated displacement of anchorage and failure mechanism:surrounding rock and soil compaction is induced by small clamping angle,instead,shear failure occurs in neighborhood soil of leading end of anchorage while clamping angle is big;anchorage length influenced surrounding rock stress as nonlinear self-organization critical characteristic on interface;anchorage size contribution to systemic primary monitor parameter is relatively uniform.Value range and contraposing design measure of anchorage topology parameter is put forward to provide theoretical basis for optimum design of suspension bridge tunnel anchorage.