Improving open bore piling and under-reaming technology

Based on the analysis of a number of domestic and foreign scientific publications, a case is made emphasizing the relevance of improving operational reliability of buildings and facilities during their construction and reconstruction through soil reinforcement by open bore piling and under-reaming. The key approaches to achieve the efficient use of enlarged-base open bore piles are identified and their advantages are discussed. The authors suggest the improved open bore piling technology for weak-soil areas featuring retrievable casing pipes and a tremie pipe-based concreting process. The pile design and piling process-related specifics are explored. The under-reaming effect is accomplished by the part of the reinforcing cage that is placed in weak soils. This cage part is made of reinforcing bars previously bent in toward the casing pipe. Before concreting, this part of reinforcing cage is shaped accordingly by applying squeeze load. The improved open bore pile is mentioned to be based on the pile design developed and patented by the authors. It is underlined that the improvement of the open bore pile design and piling technology helps reduce the metal intensity and labor cost of the process.