Yunnan Tin Company Tong Sub-pit 1725 Soft Rock Tunnel Floor Heave Control Study

Soft rock is rock with customers, such as weak, broken, loose and expansion, rheological, strong alteration, weathering and high stress of the their. With the deep shaft mining of mineral resources increasingly,the project problems of soft rock roadway , such as large deformation, heavy geostatic, supporting hardly, is getting more serious. Floor heave is the main features of soft rock roadway pressure. Floor heaved tunnel caused section narrow, impeding the transport, ventilation and staff traveling. It happens from time to time by the end of floor heaved tunnel caused abandoned. It seriously affected production and security threat. Therefore, How to effectively control of the end of floor heave has been one of the more difficult topics of soft rock roadway supporting.This paper combines elements of the 1725 soft rock roadway engineering in Yunxi tang zi wa pits, and fullly analyzed the surrounding strate's physical and mechanical properties, such as calving, pelitization, expansion of water swelling etc. On the basis of the study of large range of rock mass around the roadway, the form and thedeveloping process of its floor heave has been discussed. Floor heave deformations which arise from such factors as the elastic-plasticdeformation and the exoansion deformation resulted from rock meeting with water are estimated through theoretic computation orexperimental formulas. The roadway floor heave deformation brought about by rock creep is theoretically discussed. Thereby, the mechanism of floor heave of the roadway is profoundly exposed.In the paper, the approaches and methods of controlling the roadway floor heave are brought forward; the control schemes are composed of inverted arch strengthening and archor bolt which reinforced with both sidewall-bolt and angle-bolt. Numerical simulation using 3D-σsoftware calculated the plastic zone, safty fator, stress distribution of the three programs: the bare wall, sidewall and angle-bolt and jack arch bongding, sidewall and angle-bolt and inverted arch bongding. Analyzed the reason of the original supporting progra didn't successfully control the floor heave of the roadway. Analyzed the validity of the support program of angle-bolt and inverted arch bongding. Support scheme for the success of the scene made a good technical-economic effect. In nearly five months, the accumulated convergence deformation of the roadway is less than 7cm and deformation has basically stabilized. After a years of roadway rectification, particularly the roadway was been submerged in water circumstances, roadway maintained stability, which withstood the test of reality. Compared to repair floor heave, it saved costs 2,156 yuan / m. So the process is extensive promotional value.