江油火车站典型液化震害分析

Typical case study on liquefaction-induced damage to Jiangyou Railway Station in Wenchuan Earthquake

2008年5月12日我国四川省发生的8.0级汶川大地震中,江油火车站外表看似完好,但地基沉降、墙体开裂严重,最终不得不废弃,而周围其他建筑物破坏较轻,具有典型研究价值。通过对江油火车站进行钻孔以及现场剪切波速测试,查明了火车站破坏主因、液化主要土类,并对现有液化判别方法进行了检验。结果表明:(1)江油火车站结构振动破坏相对较轻,主要为液化导致地基沉降而最终废弃;(2)江油火车站候车室地表喷出物为粉砂,但实际液化土与喷出物差别显著,主要为砂砾土液化;(3)现有液化判别方法主要基于砂土液化资料,不适用于砂砾土的液化评价,需要研究和发展新的砂砾土液化判别方法。

The Jiangyou Railway Station looks like intact from outside ,but has to be demolished for rebuilding because of serious foundation settlement and wall crack induced significantly by liquefaction in the 2008 Wenchuan Earthquake.However, the nearby structures outside the liquefaction zone was damaged slightly. The main reason of structure damage was investigated and the liquefied soils was identified by borehole drilling, and also the current sand liquefaction evaluation method was verified by the field measured shear wave velocity. The detailed in-situ tests and verification of the current sand liquefaction assessment method revealed that： （1） The ground motion was not strong since the nearby structurewas located in the non-liquefied zone, white the foundation settlement of Jiangyou Railway Station was significantly caused by liquefaction and the railway station has to be demolished in the end. （2） The actual liquefied soils is graveland is significantly different from the spouted deposits in the waiting hall of railway station. （3） The current liquefaction evaluation method, proposed according to the sand liquefaction data, is not feasible for gravel liquefaction evaluation andthe corresponding assessment method needs to be developed.