DISCUSSION ON STRUCTURAL EFFECT TRIGGERED BY ENGINEERING EXCAVATION AND THE CONTROL MEASURES THE CASE ANALYSIS OF WEST LANZHOU SUBURB LANDSLIDE

The landslide triggered by engineering excavation depends not only by geological structure of the slope zone itself, but also by the processes between engineering excavation and geological structure effect, thus scientific engineering excavation can avert this type of geo-hazards. In the case study of landslide triggered by the excavation of deep trench for long-distance-gas pipe line on the down-dip slope of Cretaceous sandstone and the large-deformation of Lanzhou coal-gas pipe line caused by the excavation in west Lanzhou suburb on July 1st, 2001, the paper reveals the engineering excavation effect of interlayer shear zone and its control on slope stability, and then sums up the lesson in this type of geo-hazards. The authors proposed that, for prevention and reduction of this type of geo-hazards, the key measure is to firmly hold the idea that the engineering geological work must take overall situation into account and runs through the while process of the engineering project.