Hollow bar system features simultaneous drilling and grouting. It is suitable for granular soils and fills. This installation method utilises a grout swivel, grout pump and drilling head. The advanced technique combines drilling and grouting into a single operation, ensuring that grout is placed over the full length of the borehole. Simultaneous drilling and grouting is the prefered solution for ground conditions where subsequent grout injection down the center of the bar is problematical. Grouting pressures should be regulated to maintain circulation at all times, with a small amount of grout return visible at the mouth of the borehole. Pressures in excess of 100 psi are generally only required for special applications. Sinorock Self Drilling Hollow Bar System are applied in soft soil and cracked terrain. It has been used in more 100 project in China.For example,Guangxi Baise Hydropower station Project,Henan Baoquan hydropower Station Project,Chongqing Yuqian Highway Project and Hangzhou jiefang Road Tunnel Project. The Structure of Sinorock Self-Drilling Hollow Bar System is constituted with hollow bar body,self-drilling bit,centering adjustmen device,grout stop plug,PE coupling sleeve,bearing plate,and hex nut,and it can be pre-stressed. Sinorock has been awarded the task of designing and producing self drilling hollow bar for a wide range of constructions.