Research On The Principle Factors In Strength & The Damage Mechanical Model Of The Cement-lime-loess And Probability Analysis Of The Bearing Capacity Of Lime Soil Compaction Pile Composite Foundation

Lime soil is a kind of material that is used on improving ground bearing capacity and diminishing collapse of loess in the Middle & West area in China. But lime soil compaction pile is confined in many situations because it has low early strength and it can't be used in soil layers under the underground water lever. While cement is a material can harden quickly in the air and the water. Based on this point, we added some cement into lime-loess as an active material. Through six months laboratory test, mainly unconfined compression test and UU tri-axial shear test, the strength property of the cement-lime-loess with different cement content, water content and protection situation was analyzd, compared with pure lime-loess and some laws weredeveloped. At the same time, the damage stress-strain model evolution equation of cement-lime-loess was derived. Its resultnearly approached with the experiment. And the model also have the advantages of having few parameters and convenient to use.Nowadays, there are few researches on the reliability of composite foundation which uncertainty factors are more than in the natural subsoil and pile foundation as well as less materials about it. So it is necessary for us to investigate composite foundation from aspect of probability. In the paper, the probability analysis method of the bearing capacity of lime soil compaction pile composition foundation is investigated, which will push the developing of the reliability design method of composite foundation. The bearing capacity of lime soil compactionpile composition foundation is calculated using the area ratio formula, and the model uncertainty factor is also investigated through some case analysis. First, the mean and the variance of the bearing capacities of the lime soil pile and the soil between the lime soil piles are ascertained after analysis, and so the probability characteristic of the composite foundation is deduced. Then more reliable probabilistic of the bearing capacity is gained by using Bayes's theorem after considering the results of the plate-loading test.