软土固结系数刍议

Discussion on the coefficient of consolidation of soft soil

在土的固结分析中,要正确估算土体中超静孔隙水压力的消散与沉降过程,重要的是确定可靠的固结系数Cv值.通过在天仙一级公路软弱地基路基工程沿线选择的二个试验场地上开展原位试验及室内试验,并结合珠江口某海区软土的固结试验数据,研究软土固结系数的规律,探讨其确定方法.研究表明:(1)由原位孔隙水压力消散试验得到的固结系数Cv值比室内高压固结试验时间平方根法所得到的相应值大一个数量级;(2)由室内高压固结试验时间平方根法所得到的固结系数Cv值大于时间对数法、反弯点法、三点法及司各脱法所得到的Cv值.(3)由于反弯点法、三点法及司各脱法确定固结系数Cv值有其各自的优点,在实际工程中均值得去尝试和推广.

In analysis of soil consolidation,it is necessary to correctly estimate soil super static pore water pressure dissipation and settlement process,important is to determine the value of reliable consolidation coefficient Cv. In this paper,along the Tianmen-Xiantao Highway soft soil subgrade engineering choice of two test sites to carry out in-situ tests and laboratory tests,and combined with the data of soft soil consolidation tests in the Pearl River estuary. The lawof consolidation coefficient of soft soil is studied,and the method of determining the coefficient of consolidation is discussed. Research shows that：（ 1） consolidation coefficient Cvvalues obtained by the in situ pore water pressure dissipation tests are an order of magnitude larger than the corresponding values obtained by the indoor high pressure consolidation test time square root method;（ 2） consolidation coefficient Cv values obtained by the indoor high pressure consolidation test time square root method are greater than the corresponding values obtained by the time logarithm method,the inflection point method,three point method and Scott method;（ 3） due to the inflection point method,three point method and Scott method determine the consolidation coefficient Cvvalue has its respective advantages,in practical engineering are worth to try and promote.