|
North Area karst widely distributed, especially in Shaoguan, Qingyuan region, with the region's rapid economic development, county and city urban development has entered a new stage, a large number of high-rise buildings erected on the foundation and the bearing capacity demanding. Karst areas existing project risks are more common in the Karst area engineering accidents are: karst collapse, construction pile bedrock subsidence. Thus, for construction of North Karst region form the basis and foundation treatment research increasingly urgent. Rigid pile composite foundation refers to the upper structure can not meet the natural foundation bearing capacity and settlement requirements of the case, within the squeeze in the original foundation, replacement, or otherwise join the pile by pile-soil deformation coordination, and ultimately by the pile and the pile soil between the upper load shared composite reinforced foundation. South China University of Technology, Institute of tall buildings in North Karst region through a series of engineering practice proved that for the region's high-rise building structure, rigid pile composite foundation - raft foundation forms to achieve easy construction economical, safe and reliable. Rigid pile composite foundation's development is nearly a decade of thing, especially precast piles as a rigid pile composite foundation stage little research, engineering practice is not much. In this paper, the upper structure - Raft - overall composite foundation interaction analysis, Riverside Qingyuan region over a high-rise residential buildings prefabricated pile composite foundation design analysis, and follow-up site for precast pile composite foundation plate test, measuring the pile of earth pressure variation and variation of pile-soil load sharing, on this basis for the design of complex amendments to the basic configuration, and finally proposes for similar site conditions in the area of ??precast pile composite foundation macroscopic constitutive model. First, study the North Area distribution of karst geology and characteristics, and explains the Karst region project risks; through composite foundation concept, classification and mechanism, elaborated rigid pile composite foundation Research. Secondly, the upper structure - Raft - composite foundation's overall common analytical methods are summarized, and an explanation of the design with respect to different methods of conventional norms and advantages. Next, a Riverside Qingyuan region conducted a high-rise residential complex foundation design, based on the finite element analysis method of the overall co-raft foundation analysis and design, and conduct on-site and composite pile foundation plate test, measuring the pile between the mechanical properties of soil variation. Finally, based on the design of test compound to the basic configuration is corrected, made two macroscopic constitutive spring line, set the parameters and parameter analysis, given the engineering design proposals and conduct comparative analysis of the results, indicating that the new constitutive model to more accurately manner similar site conditions in the area of ??composite foundation simulation.
|