高速铁路路基下复合地基沉降计算方法

分别采用Boussinesq组合法、Boussinesq直接法、Boussinesq三角形法和德国DB836法计算地基附加应力, 采用复合模量、承载力比值法所得模量和弦线模量作为地基模量, 按12种组合形式来计算地基总沉降量, 并与某高速铁路试验段的实测沉降进行比较。计算结果表明: 当附加应力分别按Boussinesq组合法、Boussinesq直接法和德国DB836法计算, 选用复合地基载荷板试验所得弦线模量时, 计算所得的地基总沉降量同实测值非常接近, 相对差值在1.57%~9.81%之间, 满足高速铁路对地基沉降控制的精度要求。建议采用附加应力-地基模量方法进行高速铁路路基工程的地基沉降计算时, 其中附加应力可按Boussinesq组合法、Boussinesq直接法和德国DB836法计算, 地基模量选用弦线模量。

Calculation method of composite foundation settlement under high-speed railway subgrade

Boussinesq combination method, Boussinesq direct method, Boussinesq triangular method and German DB836 method were applied to calculate the foundation additional stress. Composite modulus, modulus calculated by bearing capacity ratio method, and chord modulus were applied as foundation modulus respectively. 12 combining forms were used to calculate the total foundation settlement, and the calculated results were compared with the measured settlements of test sections of high-speed railway. Calculation result shows that when foundation additional stress is calculated by Boussinesq combination method, Boussinesq direct method and German DB836 method, and foundation modulus is chord modulus calculated by composite foundation load plate test, the calculated total foundation settlements are very close to the measured value, and the relative differences are 1.57-9.81%, which can meet the requirement of foundation settlement control for high-speed railway. Therefore, it is recommended to apply additional stress-modulus method to calculate the foundation settlement of subgrade construction for high-speed railway, in which the foundation addition stress can be calculated by Boussinesq combination method, Boussinesq direct method and German DB836 method, and chord modulus is applied as foundation modulus.