G318线天全段地质环境条件较差,属于崩塌高易发区,在“4.20”芦山地震中受地震影响公路边坡共发生26处崩塌。按照形成机理,该段崩塌分为滑移式崩塌、拉裂式崩塌、倾倒式崩塌、错断式崩塌等4类,其中以滑移式崩塌及拉裂式崩塌为主。崩塌多发育在花岗岩及泥岩砂岩互层中。受余震及降雨的影响,G318线天全段的崩塌将进入高发期。 The geological conditions of G318 are very poor during the whole day, belonging to the prone areas prone to collapse. In the “4.20” Lushan earthquake, 26 collapses occurred on the highway slope. According to the formation mechanism, the collapse of the section is divided into four types, that is, slip type collapse, pull type collapse, dump collapse type and fault type collapse type, among which, slip type collapse and pull type collapse are the main types. Collapse and more development in granite and mudstone interbedded sandstone. Affected by the aftershocks and rainfall, the collapse of G318 line will enter the high incidence period.