地基系数比例系数m的计算方法研究OA

[Objective]The m-method is the most commonly used method for calculating and analyzing the internal force and deformation of pile foundations in China's railway,highway,and construction industries.At present,the relevant specifications only provide the range of the parameter m,and the specific value in design is selected based on experience,which is subjective and leads to large variations in the m-value.However,there are few studies on the theoretical analysis and calculation method of the m-value.[Methods]To investigate the theoretical calculation method of the m-value,based on the mechanical principle of the m-method for lateral soil resistance and the passive earth pressure model considering displacement,a theoretical formula that could directly calculate the m-value using shear strength parameters and deformation was established.The detailed calculation steps and procedure of the method were provided,and a calculation program was developed to achieve rapid calculation.The proposed theoretical formula for the m-value was verified and analyzed using the engineering cases of single-pile horizontal static load tests on the Yinfeng Grand Bridge of the Jinyong Railway and the Changshawan Grand Bridge of the Xiamen-Shenzhen railway.[Results]The results showed that the m-value of the Yinfeng Grand Bridge project on the Jinyong railway,calculated by the theoretical formula derived in this study,was 6 580.63 kN/m4,which was very close to the measured value 6 416 kN/m4,with a relative error of only 0.59%.The m-value obtained for the Changshawan Grand Bridge project on the Xiamen-Shenzhen railway was 4 090.60 kN/m4,which was within the range of measured on-site values(3 880～5 620 kN/m4)and was relatively conservative.[Conclusion]The proposed calculation method for the m-value can well predict the m-value of soil within the main influence range of horizontally loaded piles.