Study on Landslide Mechanism and Treatment Technology in Tunnel of Sandy Cobble Stratum

Abstract

The steady ability of sandy pebble stratum is poor, during the tunnel construction, landslides occur frequently. In order to clarify the mechanism of landslide in sand gravel tunnel and put forward effective treatment technology, the paper takes the Gongboxia tunnel, which located in Qinghai Province, as the engineering background. In view of the landslide in tunnel, the influence factors and formation instability model are analyzed, also the comprehensive treatment technology of landslide is put forward. The results show that the geological factors are the main factors of tunnel collapse, design factors and construction factors contributed to the collapse of the tunnel collapse to a certain extent, the interaction of multiple factors; sand gravel stratum collapse mechanism belongs to loose medium caving, the instability mode is gravity collapse; based on the analysis of tunnel collapse mechanism. Put forward the "dense row of short pipe shed, three bench reservation core soil + locking anchor pipe, grouting backfill, the temporary support" comprehensive treatment technology, through on-site data reflect, have very strong practicability and pertinence. The research results can provide the material of engineering analogy for the design and construction of similar projects, and have important reference significance.