The Influence Of Embedded Depth To The Box Foundation

With the development of economy, High-rise buildings, multi-story buildings and underground-garages are widely used in recent years. To satisfy the requests of utility and air defence, more and more box foundations have been adopted. This thesis analyzed the influence of embedded depth to the design of box foundation without pile.At first, comparison of different examples indicated that the foundation bearing capacity vary with the embedded depth. And contributions of the depth-revise -increment of the foundation bearing capacity and the compensate-stress-increment of the foundation to the improvement of the foundation bearing capacity are quantitatively analyzed.Secondly, this thesis analyzed the influence of the embedded depth to the corrdinateing-unequl-settlement-ability of the box foundation (overall stiffness) and the resilience-recompression of the foundation.Then, in the research of the box foundation's shear wall designing, this thesis synthesize the real examples of engineering in the past several years and present the relationships of the existing building's embedded depth with the shear wall's thickness and ratio of reinforcement in our country.Finally, this thesis focused on the study of the effects of eccentrically and horizontal loads (seismic, wind), which play an important role in confirming the embedded depth of the box foundation. Through the calculation of the stability of the foundation, derivation of the formula and engineering examples, and based on the deformation of the box foundation and the calculation methods for distribution of the stress around the foundation, taking the embedded depth (h) as target function and contacting stress of base as equilibrium condition, we derived the convenient calculation formula of the embedded depth to the design of box foundation. And the proposed theory indicated that the embedded depth of the box foundation is determined by seismic action, wind loads, soil condition and dynamic characteristic of the building structure.In conclusion, this thesis summarizes the influence of the different embedded depth to the box foundation's design, and useful method are proposed about how to get the embedded depth of the box foundation correctly and economically.