汶川8.0级地震路堑墙震害特征及机理分析

Analysis on Characteristics and Mechanism of Seismic Damage of Cutting Retaining Wall in the Wenchuan Earthquake

通过对2005年竣工的都江堰至映秀的三级公路的调查,分析了路堑墙的汶川8.0级地震震害模式;以浆砌片石典型解体崩毁工点为例,将基于抗震设计规范的验算与实震情况比较,认为现行抗震规范是按照刚性挡土墙进行设计的,对于"柔性挡土墙"并不完全适用;通过拟静力法进行计算认为墙后坡度越大,挡墙稳定性越差,未超过一定坡度时主动土压力系数增长缓慢,当超过一定坡度时,主动土压力系数急剧增长。

Based on a survey of the third-grade highway from Dujiangyan to Yingxiu built in 2005,the seismic failure types and causes of cutting retaining wall in the Wenchuan earthquake are summarized and analyzed.Taking the typical mortar flagstone site of disintegration and demise as an example,by comparative analysis of the code checking and the real seismic resistance behavior,it is thought that the current seismic design codes are designed in compliance with rigid retaining wall.The codes are not completely suitable for＂flexible retaining wall＂.The calculation by use of traditional quasistatic analytical method shows that a steeper pitch behind the retaining wall entails a worse stability.When it is not more than 25°,coefficient of active earth pressure increases slowly.Once exceed,it will be a sharp increase.