超深软基群桩综合施工技术在DFDQ项目中的应用与管理

发布时间：2018-03-30 08:47

本文选题：软土地基　切入点：静压桩　出处：《西安建筑科技大学》2015年硕士论文

【摘要】：软土地基在我国特别是沿海地区分布广泛。软土具有含水量高、孔隙比大,抗剪强度低、渗透性小等特点,且有明显的流变性和触变性。在重型工业厂房和高层建筑中,对于厚层软土的普遍采用的处理方法是采用桩基穿透软土层以达到提高承载力和减小沉降量的目的。在软土层中施工静压预应力管桩和冲孔灌注桩相较其他土体而言更加困难。本文结合DFDQ项目中静压地坪桩和墙柱下灌注桩的施工,以项目管理和经济学为理论基础,针对质量控制和安全管理等方面进行了研究。本文针对DFDQ工程中静压预应力管桩的施工,在对管桩内返土量和自引孔对返土量的影响进行研究的基础上,研发并应用了新型开口锯齿形专利桩尖,从施工方向、沉桩速率、设置防挤沟和应力释放孔等方面提出了防治挤土效应的综合施工技术措施,并对沉桩过程中的位移和孔隙水压力进行了监测。经检测证明,以上措施成功控制了静压桩的施工质量。针对超深软基中冲孔灌注桩的施工,本文从工程难点入手分析,对孔径、成孔方式、成孔工艺和施工技术参数进行研究和控制,提出了提高软土地基中施工灌注桩时的泥浆比重等技术措施,并研发和应用了新型的长空心喇叭口流线型桩锤。通过专利桩锤的应用和系列技术措施,在施工过程中成功避免了软土地基成孔易发生的塌孔、缩径等问题,提高了灌注桩的施工质量。最后,本文从制度、人员体系、材料机械设备环境管理等方面系统总结了质量、工期、安全保障措施并在工程中进行应用,实践证明以上措施达到了良好的效果。本文通过实例研究,总结了在超深软土地基中施工灌注桩和静压桩的一系列技术和管理措施,可以为后续工程提供经验借鉴,应用前景广泛。
[Abstract]:Soft soil foundation is widely distributed in China, especially in coastal areas.Soft soil has the characteristics of high water content, high porosity ratio, low shear strength and low permeability, and has obvious rheology and thixotropy.In heavy industrial buildings and high-rise buildings, pile foundation is widely used to deal with thick soft soil in order to increase the bearing capacity and reduce the settlement.It is more difficult to construct static prestressing pipe pile and punching pile in soft soil than other soil.Based on the theory of project management and economics, this paper studies the quality control and safety management based on the construction of static pressure floor pile and cast-in-place pile under wall column in DFDQ project.Aiming at the construction of static pressure prestressed pipe pile in DFDQ project, on the basis of studying the influence of the return soil quantity and self-lead hole on the return soil quantity, a new type of open sawtooth patented pile tip is developed and applied, and from the construction direction, the piling rate is studied.The comprehensive construction technical measures to prevent and control the soil squeezing effect are put forward in the aspects of setting the anti-squeezing ditch and the stress releasing hole, and the displacement and pore water pressure during the piling process are monitored.It has been proved by test that the construction quality of static pressure pile has been controlled successfully by the above measures.In view of the construction of cast-in-place pile with medium punching hole in ultra-deep soft foundation, this paper analyzes the difficulties in engineering, studies and controls the aperture, the way of hole formation, the technology of hole formation and the technical parameters of construction.This paper puts forward some technical measures such as increasing the specific gravity of mud in the construction of cast-in-place pile in soft soil foundation, and develops and applies a new type of long hollow bell-mouth streamlined pile hammer.Through the application of patented pile hammer and series of technical measures, the problems of hole collapse and diameter reduction in soft soil foundation are successfully avoided in the construction process, and the construction quality of cast-in-place pile is improved.Finally, this paper systematically summarizes the quality, duration and safety measures from the aspects of system, personnel system and environmental management of materials, machinery and equipment, and applies them to the project. The practice shows that the above measures have achieved good results.In this paper, a series of techniques and management measures for construction of cast-in-place pile and static pressure pile in ultra-deep soft soil foundation are summarized, which can provide experience and reference for subsequent projects and have a wide application prospect.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753.3

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