预压地基中止加固的综合判定

Comprehensive determination method of preloading discontinued on soft foundation

首先阐明了软基等载与超载预压的概念及工后沉降的组成,然后从土力学压缩与固结的基本原理出发,推导出能考虑等载、超载与固结度对工后沉降影响的工后主固结沉降计算式,通过预压类型系数Φ和固结度Ut把单纯考虑等载、超载工况及加固时间影响的工后主固结沉降各计算式统一于该式.式中的最终沉降量、沉降速率和β值都通过实测沉降曲线或沉降速率曲线求得,各参数间满足时间相一致的原则.利用该式对两个工程实例进行了推算,推算结果接近于实际观测值.

This paper puts forward a new calculation method of post-construction settlement for improving soft foundation by preloading.The author first clarifies the definition of preloading soft foundation by equivalent embankment weight load and over load,and the composition of post-construction settlement,and then derives the calculation formula on post-construction primary consolidation settlement from the basic principle of soil mechanics on compression and consolidation.Considering equivalent weight load,over load and degree of consolidation effects,the formula takes into account the impact of equivalent weight load and surcharge and consolidation on the post-construction primary consolidation settlement with coefficient（Ф） of preloading types and degree（Ut） of consolidation.The final settlement,the settlement rate and β values in the formula are obtained by settlement curves and settlement rate curves.Parameters in the formula need to satisfy the period corresponding guidelines.Finally,the formula is used to calculate two project examples with results agreeable to observed data.