排桩基坑设计程序编制与方案优选

发布时间：2018-11-19 14:30

【摘要】：基坑设计涉及工程地质、岩土力学、结构力学、数学、计算机编程等多方面的知识,计算过程复杂,基坑设计程序的编制对于一般的岩土专业人员来说比较困难。同时基坑设计使用的是弹性支点法,不能直接得到造价与各个影响因素之间的函数关系,不能用函数相关的知识进行优化设计。目前基坑优化设计只有试算和智能优化两类方法,这两类方法都有各自的缺陷,计算时间长且不一定能得到满意的优化方案。目前我国基坑建设数量多、规模大、造价高,具有很大的优化空间,本文对基坑优化设计进行了探讨,主要工作与研究成果如下:(1)阐述了基坑设计的基本理论和方法,设计方案优选的研究现状。分析了基坑整体稳定性随排桩嵌入深度增加而增加的规律,并将该规律应用于基坑优化设计。(2)使用C语言编写了用弹性支点法计算排桩内力的程序,并用实例检验了该程序的正确性。研究表明目前常规方法使用将土反力等效至微单元两端的简化模型时,使用结构力学位移法计算得到的弯矩、剪力有较大的误差,分析了原因并提出了相关的修正方法。(3)提出了排桩抗弯配筋计算的一种新方法并使用C编制了相关程序,经过与计算实例比较的方式验证了新方法的精确性,研究表明要得到精确的计算结果,α(排桩受压区混凝土截面面积的圆心角与2π的比值)的计算精度不宜大于0.0001。(4)用编制的程序和枚举法对某一基坑设计方案进行了优选,结果表明:在满足规范要求的情况下,优化后的方案对比原设计方案显著地降低了基坑造价。同时测试了普通电脑对基坑优化设计的计算效率,得出了普通电脑能够在短时间完成对悬臂或单道支撑排桩基坑所有方案的搜索,对更复杂的基坑所需时间太长需要使用更高级的计算机。(5)提出了枚举法结合地方经验或试算得到的规律来进行基坑优化计算的方法,验证了方法的有效性、计算的高效性,对于有地方经验的地区可以用该方法提前排除造价高的部分方案,使得普通电脑也能胜任排桩基坑的优化设计工作。(6)对基坑优化设计的发展方向进行了探讨。
[Abstract]:The foundation pit design involves engineering geology, geotechnical mechanics, structural mechanics, mathematics, computer programming and so on. The calculation process is complicated, and the programming of foundation pit design is difficult for the general geotechnical professionals. At the same time, the design of foundation pit is based on elastic fulcrum method, which can not directly obtain the functional relationship between cost and various factors, and can not use the knowledge of function to optimize the design. At present, there are only two kinds of optimization methods for foundation pit optimization, trial calculation and intelligent optimization, both of which have their own defects, and the calculation time is long and the satisfactory optimization scheme may not be obtained. At present our country foundation pit construction quantity is many, the scale is large, the cost is high, has the very big optimization space, this article has carried on the discussion to the foundation pit optimization design, the main work and the research result are as follows: (1) elaborated the foundation pit design basic theory and the method, The present situation of research on optimal selection of design schemes. This paper analyzes the law that the whole stability of foundation pit increases with the increase of the embedded depth of piles, and applies the law to the optimization design of foundation pit. (2) A program for calculating the internal force of piles with elastic fulcrum method is compiled with C language. An example is given to verify the correctness of the program. The results show that when the conventional method is used to equivalent the soil reaction force to the two ends of the micro-element, the shear force has a large error when the moment calculated by the displacement method of structural mechanics is used. The reason is analyzed and the relevant correction method is put forward. (3) A new method for calculating the flexural reinforcement of row pile is proposed and a related program is compiled with C, and the accuracy of the new method is verified by comparing with the calculation example. Research shows that to get accurate results, The calculation accuracy of 伪 (ratio of center angle of concrete section area to 2 蟺) is not greater than 0.0001. (4) the design scheme of a foundation pit is optimized by the programmed program and enumeration method. The results show that the optimized scheme can significantly reduce the cost of foundation pit compared with the original design. At the same time, the calculation efficiency of the optimization design of foundation pit by ordinary computer is tested, and it is concluded that the ordinary computer can complete the search for all schemes of cantilever or single braced foundation pit in a short time. It is necessary to use a more advanced computer for the more complicated foundation pit. (5) the enumeration method combined with local experience or the law of trial calculation is put forward to carry out the optimization calculation of foundation pit, which verifies the validity of the method. With regard to the efficiency of the calculation, for regions with local experience, some of the high-cost schemes can be eliminated in advance by this method. So that the ordinary computer can also be competent for the optimal design of pile foundation pit. (6) the development direction of the optimization design of foundation pit is discussed.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP312.1;TU473

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