CONSTRUCTION METHOD FOR TUNNEL PASSING THROUGH HIGH-ANGLE THRUST WATER-RICH AND SAND-RICH FAULT

摘要

Disclosed is a construction method for a tunnel passing through a high-angle thrust water-rich and sand-rich fault, comprising the following steps: 1, performing the preliminary excavation and the supporting construction of a rear-side tunnel section (3); 2, performing the synchronous excavation and the supporting construction of the rear-side tunnel section (3) and a drainage cave body of a drainage cave (2); 3, performing the synchronous excavation and the supporting construction of the rear-side tunnel section (3), the drainage cave body of the drainage cave (2), and a rear-side detouring heading pit (1) section; 4, performing the excavation and the supporting construction of a front drainage cave (2) body, a front heading pit section, and a central tunnel section (5); and 5, performing the excavation and the supporting construction of a front-side tunnel section (4). The water on the upper wall of the fault is drained by means of a high-level drainage cave between a tunnel main cave and a detouring heading pit, and the auxiliary drainage is performed by means of the detouring heading pit and the fault condition in front of a tunnel face of the main cave is explored in advance, thereby ensuring the construction safety of each tunnel face. The method employs a three-step method for the excavation of the tunnel main cave, employs double preliminary supporting structures for the full-section supporting of a tunnel cave after excavation, can ensure the safety of the tunnel structure later, and shortens the construction cycle.