软土地基堤围稳定性计算方法

Calculation method of stability of soft soil foundation embankment

在软土地基上采用整体稳定分析方法确定的安全系数可能会存在偏大的危险,当堤身强度高于堤基软土的强度过多时,可能存在堤基软土失稳的安全系数小于整体稳定安全系数的情况,因此,对于软土地基的堤围稳定计算,除进行整体稳定计算外,还应复核堤基软土的稳定性.并通过案例证明了该观点的正确性,同时提出了软土堤基稳定计算的方法,并以该方法为基础,提出了堤脚受冲刷情况下的整体稳定性计算方法.可为软土地基的堤围安全提供更合理安全的设计计算方法.

Strengthening the embankments on soft foundations is generally capable of improving stability.Based on this understanding,for soil foundations whose stability does not meet specification requirements,embankments are strengthened during design to improve the overall stability of the foundation.However,the actual increase is limited.In particular,for soft foundations,increase in the strength of the embankment is high will damage the foundation.Thus,the use of high-strength geotextiles is common in this situation.This study considers that the safety factor,which is usually determined using the overall stability analysis method,may feature a high level of risk.When the strength of the embankment differs considerably from the strength of the soft foundation,the safety factor of soft foundation embankment may be less than the overall stability safety factor.Therefore,to calculate the stability of soft soil foundation embankment,in addition to the overall stability calculation,the stability of the soft foundation should be reviewed.This study illustrates the correctness of this point of view.A method for calculating the stability of soft foundation is proposed.Based on this method,a calculation method for the overall stability of the embankment under scouring condition is proposed.Based on the original foundation bearing capacity model,the method considers the difference between the dike foundation and rigid foundation.Variable elasticity width fully reflects the most likely point of foundation failure occurrence when the dike is damaged.The stability of the foundation is increased by increasing the accuracy of the slip zone.Based on this method,this study also discusses the stability of the foundation under the scouring of the embankment.This method can provide a more reasonable and reliable design calculation for the safety of embankments on soft foundations.