钢筋混凝土涵洞顶部垂直土压力影响因素研究

 涵洞上覆土体采用邓肯双曲线模型、地基采用弹性模型，通过力的平衡和变形协调条件，提出涵洞土压力计算方法，并对上埋式钢筋混凝土涵洞顶部垂直土压力进行计算，由此分析了涵洞土压力的主要影响因素。结果表明：涵洞土压力系数随地基弹性模量、涵洞高宽比和填土内摩擦角的增大而增大，随填土压缩性的增大而减小，随填土高度增大呈先增后减的变化规律；填土厚度等于初始等沉面高度时，土压力系数有最大值。

Analysis on Influence Factors of Vertical Earth Pressure on Reinforced Concrete Culverts

The backfill is presented by Duncan-Chang hyperbolic model,the foundation is considered to be linear elastic and reinforced concrete culverts are considered as rigid bodies.Based on the conditions of force equilibrium and deformation harmony,the theoretical formulae of earth pressure on the culverts are derived and the main influence factors on vertical earth pressure on the reinforced concrete culverts are discussed.The results show that the coefficient,ratio of the average normal pressure acting on the roof of the culvert to the average free field pressure at the roof level,increases with the increases of modulus of elasticity of the foundation,the high-width ratio of the culverts and the angle of internal friction of backfill,and that it decreases with the increase of compressibility of the backfill,the coefficient increases first and then decreases as the buried depth increase.The coefficient is maximum when the depth of backfill equals the height of initial plane of equal settlement.