Study On Relief Of Excavation Slope Of Fossil Weathered Rock And Anchor Measure Of Gongboxia Hydroelectric Powerstation

Fossil weathered rock mass is one kind of rock mass formed with structure and strength restoring by compacted again under special geologic circumstance, which have different engineering character to modern weathered rock mass. It is certainly that the engineering character of fossil weathered rock mass will change as circumstance change. Taking fossil weathered rock mass of Gonboxia Hydroelectric Power Station as example, engineering characters are studied and mechanics parameters are defined on the base of abundant abundant field investigation and experiment. The criterion to judge the relaxation depth of rock mass of excavation slope is defined by analyzing data of sonic wave speed and field investigation, and the distributing law of various weathered degree fossil weathered rock on slope of are educed. The mechanics parameters of relaxed rock mass are studied by using relational expression between mechanics parameters and value of sonic wave speed, which provide convenience for the study of mechanics parameters of rock mass in different state. In order to restrict the displacement of relaxed rock effectively, the factors affecting the efficacy of anchor measures are analyzed according to mechanism of action of anchor. In terms of principle orthogonal design, the influence of parameters of anchor to displacement of excavation slope are elevated by computing using finite element method simulation, and the optimal scheme of anchoring parameters including length of anchors and space between bolts and thickness of shot concrete are defined. Finally, the optimal scheme of anchor parameters are determined with considering results of theory analyse and numerical calculation, which provide theory bases for engineering.