| With the implementation of the economic zone along the Yellow River and The Belt and Road construction strategy,Yinchuan's rapid economic growth,the city has been expanding,some large load,deep foundation high-rise buildings continue to emerge.The past engineering experience can not meet the needs of high-rise building construction,the problem of building foundation settlement caused by this current situation has been paid more and more attention by engineers and technicians.On the basis of summarizing the research status at home and abroad,around the issue of the relationship between compression modulus and standard penetration number and empirical coefficient of settlement calculation of silty sand in Yinchuan area etc.Based on the exploration of several construction sites in Yinchuan,Combined with laboratory test and finite element simulation analysis and other means to carry out research and obtain the following results.1.In order to determine the compression index of silty sand in Yinchuan area,in situ sampling and standard penetration test were carried out on 3 engineering sites in Yinchuan,According to the comparative analysis of compression test and standard penetration test data at different depths,the relationship between the depth Z,the compression modulus Es,and the standard penetration number N is established.The results show that,the compressive modulus of fine silty sand in Yinchuan area has a good linear correlation with the standard penetration number,the correlation coefficients were above 0.7.The linear regression equation of the compression modulus Es and the standard penetration number N is established,the compression modulus can be determined according to the standard penetration number of silty sand in Yinchuan area.2.In order to obtain the empirical coefficient of settlement calculation for Yinchuan area and accurate prediction of foundation settlement.Select a number of engineering sites in Yinchuan,calculation of ultimate settlement of building foundation by the method of layered summation,the results of theoretical calculation are compared with the measured average settlement of building foundation,the empirical coefficient of settlement calculation is obtained.Under the condition of 95%degree of confidence,the Bootstrap method is used to deduce the confidence interval of the empirical coefficient of settlement calculation is[0.104,0.130].Analysis results show,the results of this study can be used to calculate the settlement of building foundation more accurately than Empirical coefficient of settlement calculation(?s=0.2)for engineering in Yinchuan.3.Numerical simulation of settlement of building foundation based on nonlinear finite element software,this paper introduces the method and procedure of ADINA analysis of foundation settlement;The influence of the main model parameters on the results is discussed;The difference between the calculation results of the settlement of the foundation with the method of stratified summation is compared and analyzed.The analysis results show that,just like the results of the stratified summation method take empirical coefficients into account,the difference between the ADINA simulation results and the measured settlement values is small,which can be used to predict the settlement of the foundation.After considering the empirical coefficient.Under the condition of 95%degree of confidence,Bootstrap method is used to deduce the confidence interval of the empirical coefficient of settlement calculation of ADINA is[0.075,0.099].In this paper,the relationship between the compression modulus and the standard penetration number of silty sand is studied,The value of experiential coefficient of settlement calculation of building foundation in Yinchuan area is analyzed.The results of this study can provide data for the compilation of geotechnical investigation code in Ningxia area,At the same time,it also provides the reference for the geological and geotechnical engineers in Yinchuan area. |
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