Research On Strength Characteristics Of Cement Solidified Fly Ash Foundation In Xuanwei City Logistics Warehouse Storage Center Project

In the 1960s and 1970s,a large number of waste fly ash were backfilled in the field environment in China,a large number of land was occupied,resulting in waste of resources.In order to save arable land and make comprehensive use of waste land,Huafu cold chain warehouse center logistics project in Xuanwei City,Yunnan Province is located in the waste fly ash discharge field of Xuanwei thermal power plant.This kind of fly ash stratum which has been backfilled for many years belongs to soft foundation,so it must be reinforced.For this reason,this subject takes the fly ash foundation which has been backfilled for many years as the research object,and the cement soil mixing method is designed for foundation treatment.This method can be used to improve the bearing capacity and stability of the foundation and provide theoretical guidance for the treatment of flyash foundation in engineering.Through the work,the paper has achieved the following understanding and results:(1)Based on the exploration of the site and the analysis of the properties of fly ash in combination with the indoor geotechnical test,it is found that the fly ash in the proposed industrial area belongs to the low calcium undisturbed fly ash,with an average thickness of 10m and a maximum thickness of 25m,and the type of combustion belongs to class F;the fly ash in the site belongs to the class of fly ash in the engineering classification design,and the bearing capacity of the natural foundation is about 123.33kpa.(2)Through the exploration of the principle of cement solidified fly ash and active excitation mechanism,the unconfined compressive strength test of fly ash test block is carried out by choosing different cement content,different age and different active activator.On this basis,the influence law of three factors on the compressive strength is found out by using MATLAB data fitting analysis.The formula of power function can be obtained by a single influence factor,such as:F(x)(28)a(9)x~b;the polynomial formula can be obtained under the influence of multiple factorsF(x,y)(28)p00(10)p10(9)x(10)p01(9)y(10)p11(9)x(9)y(10)p02(9)y~2(10)p12(9)x(9)y~2(10)p03(9)y~3(28)F(z).(3)Compared with the original design of 20%cement content,the 15%cement content selected in this paper is the most economical and applicable,and the activator can be added selectively.