Loose Rock Group Hole Stability Of Surrounding Rocks

There is plenty of Relaxed Rock Mass in Huanghe Heisanxia Daliushu dam site, which results from itself soft-rigid nature acting with the special area stability dynamics condition. In Relaxed Rock Mass, plenty of faults and holes can be found, the wave is slow, the permeability is high, and the groundwater level is deep. As cavities' surrounding rock, Relaxed Rock Mass is cracked, much of which belong to â…¢ and â…£ rank surrounding rock, and the â…£ rank rock is majority. In this thesis, large numbers of data have been studied. Daliushu dam site cavities distributed along the 3th exploration line are the research objective, the Relaxed Rock Mass Multi-cavity effect, under gravity, groundwater seepage, dynamic and multi field coupling acting condition, has been systematically researched firstly, by using numerical method, based on equivalent continuum theory. The result shows: (1)The Multi-cavity effect is sharp, especially In the surrounding rock between the five close diversion cavities, the stress is twice larger then before, and the local area in which the rock is in plastic intercommunicates each other. The distributing character of the stress in surrounding rock is affected by the existence of weak zone ji22; (2) The seepage of groundwater results in the effect sharper then before, owe to the high permeability of Relaxed Rock Mass. The groundwater reduces the strength of surrounding rock by reducing the effective stress of the rock, as the result, the shear strain increment in the area of cavities is larger then before, and the surrounding rock on cavity wall changes its plastic form from shear to tensile; (3) By comparing the earthquake response of single cavity with which of cavities, it is be observed that the acceleration of cavities is higher then which of single cavity; (4) Under multi-filed coupling acting condition, the earthquake makes the rock more relaxed and more expansion then before, so the effective stress become higher and the exceed hydraulic pressure can not be found.In this thesis, the status of cavitation of single cavity and cavities in Relaxed Rock Mass, the adaptability of bolt-reinforcement to the â…¢ and â…£ rank surrounding rock and the stability of bolt-reinforcement surrounding rock under earthquake condition has been researched based on non-equivalent continuum theory. The result says: (1) The stability of single cavity surrounding rock in Relaxed Rock Mass is poor, large scope of wreck and collapse rock can be found. As for Multi-cavity effect, the stability of multi-cavity surrounding rock is more bad then the single's, and theworst is not on the tip of the cavity wall, but on the side of surrounding rock lean to the other cavity; (2) The adaptability of bolt-reinforcement to IV rank surrounding rock is bad, and the IV rank surrounding rock need to be grouted; (3) Based on elastic-creep model theory, the long-time strain of bolt-reinforcement surrounding rock has been forecasted, and the long-time displacement of Illrank rock is 16.8mm and which of IV rank rock is 22.7mm; (4) Under earthquake condition, the bolt-reinforcement surrounding rock with good stability is also stable, but the one with bad stability becomes worse then before; (5) The bolt-reinforcement strengths the surrounding rock to withstand earthquake by enhancing the shear strength and tensile strength of which.