Construction method of controlling dam foundation rock mass excavation relaxation through prestress anchoring

Abstract

The invention relates to a construction method of controlling dam foundation rock mass excavation relaxation through prestress anchoring. The invention aims at providing a construction method of controlling dam foundation rock mass excavation relaxation through prestress anchoring so as to reduce the effect of excavation stress relief unloading relaxation on the dam foundation rock mass quality and improve the safety of the dam, the construction method is convenient to execute, and the construction cost is low. The technical scheme of the invention is as follows: the construction method of controlling dam foundation rock mass excavation relaxation through prestress anchoring is characterized by comprising the following steps of: a. performing dam foundation excavation construction and preserving a protection layer above a foundation base; b. drilling anchor rod holes on the top face of the protection layer, arranging detachable prestress anchor rods in the holes and applying prestresss on the anchor rods; c. injecting anchoring mortar in the anchor rod holes below the protection layer; d. detaching the connecting rods in the protection layer after the anchoring mortar is solidified; and e. finally excavating the protection layer. The construction method provided by the invention is suitable for foundation excavation construction of easily relaxed rock mass in hydraulic and hydroelectric engineering.

Description

technical field [0001] The invention relates to a construction method for controlling the excavation relaxation of dam foundation rock mass by adopting prestressed anchorage. It is suitable for foundation excavation construction where the rock mass is easy to relax in water conservancy and hydropower projects. Background technique [0002] With the development of the national economy, a large number of water conservancy and hydropower projects need to be built in the west of my country. These projects often encounter complex geological conditions, such as high ground stress and the development of primary joints and fissures in the rock mass. The physical and mechanical properties of the undisturbed rock mass in the high geostress area and the rock mass with primary joints under confining pressure can often meet the requirements of the foundation surface of the dam, but the release of confining pressure stress and blasting vibration caused by excavation is easy to This will ...

AI Technical Summary

Problems solved by technology

The physical and mechanical properties of the undisturbed rock mass in the high geostress area and the rock mass with primary joints under confining pressure can often meet the requirements of the foundation surface of the dam, but the release of confining pressure stress and blasting vibration caused by excavation is easy to This will lead to relaxation and deformation of the rock mass, and even the formation of horizontal unloading cracks, which will reduce the mechanical indicators such as shear strength and deformation modulus of the rock mass within the affected area, increase the water permeability of the rock mass, and seriously affect the foundation rock of the dam. body mass, reducing the safety of the dam

Images