基于非参数回归的基坑支护动态优化设计

发布时间：2018-04-25 17:25

本文选题：基坑 + Monte　；参考：《昆明理工大学》2017年硕士论文

【摘要】：目前我国基坑工程由于受到建设场地大小的限制,其建设规模朝着越来越深的方向发展。随着深基坑工程数量与规模的增加,深基坑支护结构的安全性与经济性受到人们的更多关注。现有的深基坑施工方法有顺作法和逆作法之分,但是无论采取何种施工方法基坑工程在设计与施工阶段便面临许多不确定因素如:地质条件、地下水情况、天气变化的影响、场地周边环境、施工人员管理等,其中首要问题就是土体参数选取的复杂性。因此基于工程勘察所得的土体参数进行基坑支护结构设计(静态设计),可能是过于保守的从而在经济性上并不合适。其次在深基坑的施工过程中,对土体本身造成了扰动从而导致土体力学参数发生了变化,施工场地周边环境也会随之产生改变,按勘察所得土体力学参数进行的原有支护设计可能因为这些变化随之变得不再安全可靠。为了能解决目前基坑静态设计方案的不足之处,我们可以采用动态设计的理念来进行深基坑的施工设计。所谓的动态优化设计理念即在施工过程中根据实时监测反馈得到的信息来对土体参数进行反分析,根据反分析所得土体等效参数对施工工艺以及原有支护结构设计进行优化调整,使得施工设计达到更加安全和经济的目的,并不断优化改进的过程。其中在动态优化设计过程中对土体参数进行反分析方法的选取尤为重要,因此本文提出了一种基于非参数回归的反分析方法为深基坑支护的动态设计提供新的研究思路。本文的动态设计理念是基于均匀试验和非参数回归技术建立响应面,在响应面的基础上根据实时监测得到的反馈信息,结合Monte Carlo模拟技术对土体参数的取值进行反分析,用反分析所得等效参数对原设计的支护结构进行动态设计优化调整。并将该方法应用于桩锚支护和内撑环支护两种不同的实际工程案例中,用动态设计优化后的支护结构方案与原设计方案进行对比分析,以证明该方法在深基坑支护动态设计中具有较好的普遍适用性。
[Abstract]:At present, the construction scale of foundation pit engineering in our country is more and more deep because of the limitation of construction site size. With the increase of the quantity and scale of deep foundation pit engineering, people pay more attention to the safety and economy of deep foundation pit supporting structure. The existing methods of deep foundation pit construction can be divided into normal and reverse methods. However, no matter what construction method is adopted, many uncertain factors such as geological conditions, groundwater conditions and weather changes will be faced in the design and construction stage of foundation pit engineering. The complexity of selecting soil parameters is the most important problem in the environment around the site and the management of construction personnel. Therefore, the design of foundation pit support structure based on the soil parameters obtained from engineering survey (static design) may be too conservative and therefore not suitable for economy. Secondly, during the construction of deep foundation pit, the soil itself is disturbed, which results in the change of soil mechanical parameters, and the surrounding environment of the construction site will also change. The original support design based on the mechanical parameters of the surveyed soil may become unsafe and reliable as a result of these changes. In order to solve the shortcomings of the static design of foundation pit, we can use the idea of dynamic design to design the deep foundation pit. The so-called dynamic optimization design concept is to carry out back analysis of soil parameters according to the information obtained from real-time monitoring feedback in the construction process. According to the equivalent parameters of soil mass obtained from back analysis, the construction technology and the original support structure design are optimized and adjusted, which makes the construction design more safe and economical, and the process of continuous optimization and improvement is optimized. In the process of dynamic optimization design, it is very important to select the back analysis method of soil parameters. Therefore, a new method based on non-parametric regression is proposed in this paper to provide a new research idea for the dynamic design of deep foundation pit support. The dynamic design idea of this paper is to establish the response surface based on uniform test and non-parametric regression technique. Based on the feedback information obtained from real-time monitoring and Monte Carlo simulation technology, the parameters of soil are back analyzed. The dynamic design optimization adjustment of the original support structure is carried out by using the equivalent parameters obtained from the back analysis. The method is applied to two kinds of practical engineering cases of pile anchor support and inner bracing ring support. The optimized support structure scheme after dynamic design is compared with the original design scheme. It is proved that this method has good general applicability in the dynamic design of deep foundation pit support.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473

【参考文献】