The Typical Bank Slope Of The Dadu River In The Middle And Lower Reaches Of Deep Cracks Formation Mechanism And Engineering Effects

Natural slope usually has a zestier of strong unloading and a zestier of weak unloading and corresponding zone of strong (or weak) weathering, and there is integrity fresh rock in its inside. But there is a series of sheeted crack or zone of crack inside normal unloading zone that was named as deep crack. Deep crack is a specific and complicated deformation of high-steep rock slopes. Different types of deep crack have different meaning to slope stability. So, it is important to distinguish the type of deep crack and analyze the formation mechanism of deep fracture in exploring and studying large slope of hydropower station. The study on deep crack of rock slopes can play important role in prevention and mitigation of geo-hazards and construction of infrastructures in mountainous areas.This paper takes the deep crack in Typical Slopes of Middle and Lower Reaches of the Dadu River as a study object, collected former study information and explored the evolvement of river valley in Middle and Lower Reaches of the Dadu River. On the basis of analyzed rock mass structure and rock mass quality and distributing characteristic of deep crack, it is the core of the study that epigenetic reformation by unloading effect of river valley and release of high geostatic stress. This paper systemically and thoroughly studies the deep crack in Typical Slopes of Middle and Lower Reaches of the Dadu River, and focused on the influence factors that can come into being deep crack of typical slopes.This paper has studied the rock of the typical slope under triaxial unloading test, and analyzed the influence that unloading speed and enclose press and axial press is to the rock mechanics capability. With comparing triaxial unloading test to unloading by the quickly corroding of river valley, this paper has understood the processing of slope from the point of view of unloading.On the basis of systemically and thoroughly studying geology and environment foundation of the deep crack, this paper has established the formation mechanism of deep crack. Thereafter, this paper point out the deep crack was the result of epigenetic reformation by unloading effect of river valley and release of high geostatic stress.Finally, by way of analyzed the characteristic of distributing and deformed of the deep crack, this paper has studied the influence that the deep crack is to human engineering construction, and analyzed the influence that the deep crack is to the leakage of reservoir and the stability of slope and the stability of the surrounding rock of underground excavation.