银川地区粉细砂土的压缩模量与沉降计算经验系数取值研究

发布时间：2018-05-19 12:12

本文选题：粉细砂土 + 压缩模量　；参考：《宁夏大学》2017年硕士论文

【摘要】：伴随沿黄经济区及“一带一路”建设战略的实施,银川地区经济快速增长、城市规模不断扩大,一些大载荷、深基础的高层建筑不断涌现。以往的工程经验并不能很好的满足高层建筑建设的需求,由此引发的建筑地基沉降问题越来越引起工程技术人员的重视。本文在总结国内外研究现状的基础上,围绕着银川地区粉细砂土的压缩模量与标贯击数的相关关系、建筑地基沉降计算经验系数等问题,以银川市区多处建筑工程场地现场勘探为依托,结合室内试验及有限元仿真分析等手段开展研究并获得以下成果:1.为合理确定银川地区粉细砂土的压缩指标,依托银川市区3处工程场地进行原位取样和标贯试验,根据不同深度处压缩试验与标贯试验数据的对比分析,建立了粉细砂地层深度Z、压缩模量Es、标贯击数N三者之间的对应关系。研究结果表明,银川地区粉细砂土的压缩模量Es与标贯击数N具有良好的线性相关性,相关系数均达0.7以上。建立压缩模量Es与标贯击数N的线性回归方程,根据银川地区粉细砂土的标贯击数即可确定其压缩模量。2.为获得适合银川地区的建筑地基沉降计算经验系数,准确预测建筑物地基沉降。选取银川地区的多处工程场地,采用分层总和法计算建筑地基最终沉降量,将理论计算的结果对比建筑物地基实测平均沉降量,得出沉降计算经验系数Ψs,在置信度为95%的条件下,采用Bootstrap法推断出沉降计算经验系数的置信区间为[0.104,0.130]。分析结果表明,研究结果相比银川地区工程经验所取用的沉降计算经验系数(Ψs=0.2),可更加准确计算建筑地基沉降。3基于ADINA非线性有限元软件对建筑地基沉降进行数值模拟,介绍了 ADINA分析建筑物地基沉降的方法和步骤;探讨了主要模型参数对计算结果的影响;对比分析了与分层总和法地基沉降计算结果的差异。分析结果表明,类似分层总和法计算结果考虑沉降经验系数,ADINA模拟结果修正后对比实测沉降值相差较小,可以为预测建筑物地基沉降提供参考。在置信度为95%的条件下,采用Bootstrap法推断出对应ADINA的沉降计算经验系数的置信区间为[0.075,0.099]。论文研究明确了银川地区粉细砂土的压缩模量与标贯击数的关系,分析了银川地区建筑地基沉降计算经验系数的取值,该研究结果的获得可为宁夏地区岩土工程勘察规范的编制提供数据积累,同时也为银川地区广大地质和岩土工程设计人员提供参考和借鉴。
[Abstract]:With the implementation of the economic zone along the Yellow River and the construction strategy of "Belt and Road", the economy of Yinchuan area is growing rapidly, the scale of the city is expanding, and some high-rise buildings with large load and deep foundation are emerging. The previous engineering experience can not meet the needs of high-rise building construction, and the settlement of building foundation caused by it has been paid more and more attention by engineers and technicians. On the basis of summing up the present research situation at home and abroad, this paper focuses on the correlation between the modulus of compression of silty sand soil and the standard penetration number in Yinchuan area, the empirical coefficient of settlement calculation of building foundation, and so on. Based on the field exploration of many building engineering sites in Yinchuan city, the research was carried out by means of indoor test and finite element simulation analysis, and the following results were obtained: 1. In order to reasonably determine the compression index of silty sand soil in Yinchuan area, based on the in-situ sampling and standard penetration test of three engineering sites in Yinchuan City, the compression test and the standard penetration test data at different depths are compared and analyzed. The corresponding relationships among depth of silty sand Z, modulus of compression Esand and number of strike N are established. The results show that the modulus of compression (es) of silty sand in Yinchuan area has a good linear correlation with the standard punch number N, and the correlation coefficients are above 0.7. A linear regression equation between modulus of compression (es) and standard punch number (N) was established. The compression modulus of silty sand soil in Yinchuan area could be determined by the standard impact number of sand soil. In order to obtain the empirical coefficient of building foundation settlement which is suitable for Yinchuan area, the settlement of building foundation can be accurately predicted. The final settlement of building foundation is calculated by stratified summation method in many engineering sites in Yinchuan area. The results of theoretical calculation are compared with the measured average settlement of building foundation. Under the condition of 95% confidence, the confidence interval of empirical coefficient of settlement calculation is [0.104 ~ 0.130] by Bootstrap method. The analysis results show that compared with the calculated empirical coefficient of settlement in Yinchuan area, the settlement of building foundation can be calculated more accurately. 3. Numerical simulation of foundation settlement is carried out on the basis of ADINA nonlinear finite element software. This paper introduces the method and procedure of ADINA analysis of foundation settlement of buildings, discusses the influence of main model parameters on the calculation results, and compares and analyzes the difference between the calculation results of foundation settlement and that of stratified summation method. The analysis results show that the calculated results of the similar stratified summation method take into account the empirical coefficient of settlement and the results of Adina simulation have little difference compared with the measured settlement values, which can provide a reference for predicting the foundation settlement of buildings. Under the condition of 95% confidence, the confidence interval of empirical coefficient of settlement calculated by Bootstrap method is [0.075 卤0.099]. In this paper, the relation between the modulus of compression and the number of standard penetration of silty sand soil in Yinchuan area is studied, and the value of empirical coefficient of settlement calculation in Yinchuan area is analyzed. The results of this study can provide data accumulation for the compilation of geotechnical engineering survey code in Ningxia area, and also provide reference for the vast number of geological and geotechnical engineering designers in Yinchuan area.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU441

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