一、引言我国《铁路工程技术范围》第二篇桥涵中规定桩基内力计算要考虑土的弹性抗力,并假定地基系数在地面处为零,随深度呈线性变化(m法)。对砂性土来说,假定地面处的地基系数为零是无可非议的。但就粘性土而论,只要表层土尚未屈服,就不应将地面处的地基系数假定为零。文 I. INTRODUCTION The second bridge and culvert in China’s “railway engineering technical range” stipulates that the elastic resistance of soil should be taken into account when calculating the internal force of pile foundation. It is assumed that the ground-based coefficient is zero at the ground surface and changes linearly with depth (m). For sandy soil, it is unquestionable to assume that the ground factor at the ground is zero. However, in the case of cohesive soils, the foundation factor at the ground should not be assumed to be zero as long as the topsoil has not bowed. Text