In order to solve the problems of steep— inclined limestone，poor self support capability of weak and soft shale and difficulties in the control of the rock mass deformation in the construction of the underground powerplant of Pengshui hydropower station，the new technology of expansion and prestressed type hollow grouting bolt with steel wedge is adopted to reinforce the shallow— covered rock mass．The anchor piers with steel plates，which are used to replace the original concrete anchor pier s，can simplify the construction technology，ensure the construction quality and enhance the construction speed．Thus，the wall rocks are deeply and immediately anchored and the deformation risks of the wall rocks are minimized．The comprehensive application of the new anchoring technology ensures the shallow and／or deep anchoring quality in soft and weak shale．In addition，the new technology results in significant economic and social benefits and can be popularized．
Sinorock is recognized for its excellent quality, delivery performance, innovative management and perfect service system. In addition, many products we have developed have become industry standards. The products we are provide all kinds of self drilling hollow bar and the corresponding accessories. Our self drilling hollow anchor bolt products received the consistent high praise by the customers. Till now, Sinorock has become one of the famous self drilling hollow bar suppliers.