匝道爆破开挖中保护埋地管线的贝雷梁应用研究

以泸州市沱江四桥及连接线工程为背景，介绍并分析了爆破开挖时利用贝雷桁架结构保护管线的措施。首先在静力条件下，利用解析法和数值模拟方法对结构进行安全检算；其次，运用ANSYS/LS-DYNA模拟爆破开挖，将得到的振动加速度施加到结构上并进行动力响应分析，得到贝雷梁最大变形19.9 mm，最大压应力90.5 MPa，最大拉应力36.1 MPa，满足变形及强度要求；最后，运用ANSYS分析结构的动力特性。结果表明:结构的自振频率远小于爆破振动频率，且在水平面上垂直顺梁的方向结构最易变形。

Study on Application of Bailey Beam for Buried Pipeline Protection in Blasting Excavation of Ramp

Based on Tuojiang Bridge 4, Luzhou City and the connection line engineering, the measures using Bailey truss for pipeline protection in blasting excavation were introduced and analyzed. Firstly, the structure safety was checked under the static condition by analytical method and numerical simulation method. Secondly, in the blasting excavation imitated by ANSYS/LS-DYNA, the vibration acceleration obtained was applied on the structure and, with the dynamic response analyzed, it was solved that the maximum deformation of the Bailey beam was 19.9 mm, the maximum compression stress 90.5 MPa, and the maximum tensile stress 36.1 MPa, meeting the requirement of deformation and strength. Finally, the structure dynamic characteristics was analyzed with ANSYS. The result shows that the natural vibration frequency of the structure is far less than the blasting vibration frequency, and the structure is mostly pronet odeformation in the direction perpendicular to the beam on a horizontal plane.