Open cut tunnel and bridge combined underpinning integrated construction method

Abstract

The invention provides an open cut tunnel and bridge underpinning combined integrated construction method, belongs to the technical field of rail transit deep foundation pit engineering, and aims to meet the requirements of rapid construction of an underpass tunnel and normal passage of an upper bridge at the same time. The method comprises the steps that firstly, supporting piles, underpinning piles and fender posts are constructed; 2, the jacking holding force of the auxiliary pier is set, and the stand column is hooped; thirdly, slope excavation is conducted till the underpinning bearing platform bottom is reached, stand columns are cut off, and old bearing platforms and old pile foundations which conflict with the tunnel structure and the first horizontal supports at the upper end and the lower end are chiseled away; fourthly, water cutting is conducted on stand columns, a top ring beam and first horizontal supports at the upper end and the lower end are constructed, and then an underpinning bearing platform is constructed; fifthly, after the underpinning bearing platform reaches the design strength, the auxiliary piers are dismantled, the bearing piles are pulled out, and pile bodies on the upper portions of the shared fender posts are cut off to the elevation of the top ring beam; sixthly, foundation pit earth excavation is conducted layer by layer, and supports below the first horizontal supports at the upper end and the lower end are poured and erected; and seventhly, after excavation is conducted to the base, a tunnel structure is built back, the horizontal supports are dismantled, and construction is completed.

Description

technical field [0001] The invention relates to the technical field of rail transit deep foundation pit engineering, in particular to an integrated construction method for open-cut tunnels combined with bridge underpinning. Background technique [0002] The east-west expressway underpass project of a project includes ground roads and underpass tunnels. The project is arranged along the east-west avenue of the main road in the existing urban area. After passing through a section of ground, it will continuously pass through the provincial road and the viaduct in the form of tunnels, and the main line tunnel will pass through the high-speed ramp bridge and the main viaduct bridge. Among them, most of the pier caps of a certain bridge are located inside the west line tunnel, which interferes with the plane of the west line tunnel, and there is a plane conflict between the two. The pile foundation of the cap will hinder the excavation of the tunnel foundation pit. The plan origi...

AI Technical Summary

Problems solved by technology

Since the East-West Avenue is the main road in the city, vehicles pass frequently and the traffic flow is huge. The construction party requires that the tunnel crossing construction must ensure the normal traffic capacity of the elevated road. Therefore, the feasibility of the reconstruction plan is ruled out. Arranged so that the tunnel cannot pass under or through the pile foundations

The existing conventional foundation pit cut-and-cut support technology is difficult to meet the goal of rapid construction of the lower tunnel and the normal passage of the upper bridge

Images