局部剪切破坏是一种常见的地基破坏模式,该破坏模式下的地基承载力理论计算方法尚不完善,对无重地基局部剪切破坏的极限承载力理论进行了研究。首先从破坏时破裂面延伸位置的角度完善了浅基础3种破坏模式的划分标准。对于局部剪切破坏,土体强度并未完全发挥出来,潜在破坏区处于非极限状态,所以将土体强度逐渐发挥的概念引入地基承载力中,通过适当的假设,建立了局部剪切破坏模式下无重介质地基承载力的理论计算方法,并与已有的经典成果进行比较分析,印证了该方法的合理性。研究成果为解决局部剪切破坏模式下地基承载力的计算提供了理论参考。
Local shear failure is a kind of common mode of foundation failure; but the calculation method of bearing capacity under local shear failure mode is not sufficiently studied so far. Therefore a theoretical calculation method is proposed. Firstly, classification standard of shallow foundation failure modes is revised based on the extension position of slip surface under failure state. The shear strength of potential failure surface under local shear failure is partially worked out; subsequently the concept model of shear strength progressive work is introduced into the bearing capacity of foundation; and the calculation method of weightless foundation bearing capacity under local shear failure is also obtained using proper supposition. A comparison between some known empirical formulas and the present method is offered and the suitability of the present method is verified. The results provide theoretical references for the bearing capacity of the foundation under local shear failure mode.