黄土公路隧道衬砌受力特性测试研究

通过对浅埋黄土公路隧道衬砌受力现场测试,研究了隧道衬砌围岩压力、钢花拱轴力和二次衬砌混凝土应变随时间变化以及不同位置分布情况。结果表明:拱部和边墙围岩压力先是增大后减小然后趋于稳定,隧道周围土体有局部坍塌的可能,按实测值推算的竖向围岩压力小于按已有公式计算的值,钢花拱轴力稳定较快且以受压为主,二次衬砌和仰拱的承载作用并不明显。

Observation research on the mechanical characteristic of highway tunnel lining in loess

Through observation in field of the shallow highway tunnel lining in loess, authors research the change of the surrounding rock pressure on tunnel lining, the axial force of lattice girder and the strain of second lining to the time and the distribution in different positions. The results show the pressure on arch and side wall increases at first, then, decreases and finally keeps steady, surrounding soil has the probability of collapse, vertical pressure calculated by the test results is much less than the pressure by three formula, axial force of the lattice girder become steady in the short time, lattice girder is at pressure in majority,and the bearing functions of second lining and invert are not obvious.