Study Of Bearing Capacity Of Pile Foundation In Expansive Soil Field In Qiqihar

The pile foundation is an important foundation commonly adopted in the Modern Civil Engineering.The working performance of the pile foundation is determined by the engineering property of foundation soil.The expansive soil in Qiqihar closes to ordinary cohesive soil,which is misjudged to ordinary cohesive soil in the construction of engineering.If designing the pile foundation in accordance with the national unified standard,often causes the area pile foundation engineering design to cause the economic loss.Obviously,it is important to study the engineering properties of Qiqihar expansive soil and the design calculation method of pile foundation,which has important theoretical significance and practical value.In this paper,by collecting and analyzing data of construction site engineering geological survey in Qiqihar area,the distribution and physical and mechanical indexes of main strata in Qiqihar are given,and the characteristics of the expansive soil in Qiqihar area are pointed out.According to the provisions of "GB"(50112-2013),the expansive soil is determined.And miscellaneous fill or cultivated soil distribution is not uniform,the soil’s compressibility is bigger,the intensity is lower.Through analysis of the static load test curve and its bearing capacity of pile foundation,it is pointed out that the bearing capacity of the foundation of expansive soil in Qiqihar area is much lower than that of the common cohesive soil foundation,when according to the national standards and specifications for design and calculation of pile bearing capacity,the multiplied by 0.4~0.5 reduction coefficient.The static load test curve of the pile is put forward,and then the bearing capacity of the pile is determined.The load bearing capacity of the piles in the Qiqihar expansive soil is studied by using the static load test and the static load test.It is pointed out that the development of single pile bearing capacity of Run Run Shaw Teaching Building in Qiqihar University can be improved by 1.5 times of the initial test value.Based on the analysis of the experimental results of the static load test of the foundation pile of Run Run Shaw Teaching Building in Qiqihar University,the empirical formula of the relationship between the bearing capacity of single pile and the time is given,and the maximum error is 1.5%.