高压旋喷微型桩支护结构支护机理与设计计算研究

发布时间：2018-01-11 11:12

本文关键词：高压旋喷微型桩支护结构支护机理与设计计算研究　出处：《西南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：微型桩支护结构作为新型基坑支护结构,具有施工快捷安全、经济效益好、土体扰动小、场地适应性强等优点。由于缺乏其支护受力机理方面的研究,严重制约了微型桩支护结构的推广应用。本文利用实际工程数据,建立有限元模型,并与实测数据对比,验证了模型有效性,通过数值模拟的手段研究了微型桩支护体系的受力机理,主要研究内容和结论如下:旋喷微型桩支护结构现阶段设计是按照重力式水泥土墙设计,对其进行了系统整理和分析,并对现场监测数据整理和分析。实测数据表明,桩顶位移基本小于10mm,远小于规范限定值24mm,设计偏保守;桩沿深度的水平位移,桩的变形符合弯曲变形的特征。故按照重力式水泥土墙设计旋喷微型桩支护结构是不合理的。根据工程实际情况和工程参数确定基准工况,并建立微型桩支护结构三维有限元模型,选择ABAQUS中合适的材料本构模型。对微型桩支护结构受力主要影响因素如有无钢筋、有无冠梁、桩间距以及排间距等进行了分组建模分析,主要研究了各排桩的水平位移、水平弯矩、水平剪力、土压力以及各排桩土压力分担比等,得出了各因素对微型桩支护桩结构受力的影响规律,并据此分析了微型桩支护结构在深基坑开挖中的受力机理。
[Abstract]:As a new type of foundation pit support structure, micro-pile support structure has the advantages of fast construction, safe construction, good economic benefit, small soil disturbance, strong site adaptability and so on. In this paper, the finite element model is established by using the actual engineering data, and compared with the measured data, the validity of the model is verified. The mechanical mechanism of micro-pile support system is studied by numerical simulation. The main research contents and conclusions are as follows: the design of rotary jet micro-pile support structure is based on gravity cement soil wall design at the present stage. It is systematically arranged and analyzed, and the field monitoring data are analyzed. The measured data show that the displacement of the pile top is less than 10mm, far less than the limited value of 24mm, and the design is conservative. The horizontal displacement of the pile along the depth. The deformation of pile accords with the characteristic of bending deformation, so it is unreasonable to design the micro-pile supporting structure based on gravity cement-soil wall. The three-dimensional finite element model of micro-pile supporting structure is established, and the suitable material constitutive model in ABAQUS is selected. The main factors affecting the force of micro-pile supporting structure such as steel bar and crown beam are discussed. Group modeling and analysis of pile spacing and row spacing are carried out, and the horizontal displacement, bending moment, horizontal shear force, earth pressure and the proportion of soil pressure of each row pile are mainly studied. The influence of various factors on the stress of micro-pile supporting pile structure is obtained, and the mechanical mechanism of micro-pile supporting structure in deep foundation pit excavation is analyzed accordingly.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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