竖向开孔基坑内支撑梁静爆拆除法及模型数值模拟

发布时间：2018-10-26 14:32

【摘要】：随着基坑内支撑梁拆除技术的发展,人们对于拆除技术的环保要求也越来越高,低噪音、低粉尘、拆除效率高的绿色施工工艺越来越受到土木行业的青睐。软土地区深基坑内钢筋混凝土支撑梁在拆除过程中的噪音、粉尘等会对环境造成很大影响,阻碍了绿色施工技术的实施,同时也增加了施工成本、施工工期和安全隐患。为减少上述各种因素的影响,本文提出一种新的静爆破碎法,即在混凝土支撑梁施工时,预设一定直径的孔洞,然后使用破碎剂将内支撑梁静爆破碎。经试验并在工程中应用,支撑梁在灌药后的预设时间内刚性整体基本被破碎完成,便于后期轻易拆除。该技术大大节约了成本,缩短了拆除的施工工期,施工工艺简单,便于推广应用。本文提出的新型静态爆破技术中要在钢筋混凝土内支撑梁上布置均匀的孔洞,用来作为后期的爆破灌药孔,关于孔洞对于梁整体的受力性能的影响则需要使用ABAQUS有限元软件进行模拟。本文截取内支撑群梁中的一榀梁作为研究对象,在软件中建立带孔梁模型,在梁的端部施加固定约束,于梁顶部施加均布荷载,待钢筋混凝土梁中的钢筋达到屈服,运算结束。通过分析模型梁的荷载位移曲线,确定其新的承载能力。
[Abstract]:With the development of the technology of removing the supporting beam in the foundation pit, the green construction technology with low noise, low dust and high removal efficiency is more and more popular in the civil engineering industry. The noise and dust of reinforced concrete bracing beam in deep foundation pit in soft soil area will have a great impact on the environment and hinder the implementation of green construction technology. At the same time, the construction cost, construction time limit and hidden danger of safety will be increased. In order to reduce the influence of the above factors, a new method of static blasting breakage is proposed in this paper, in which the holes with a certain diameter are preset during the construction of the concrete supporting beam, and then the inner bracing beam is broken by the crushing agent. After test and application in the project, the rigid whole of the support beam is basically broken and completed in the preset time after pouring, which is easy to remove in the later stage. This technology greatly saves the cost, shortens the construction period of demolition, and the construction technology is simple and easy to be popularized and applied. In the new static blasting technology proposed in this paper, uniform holes should be arranged on the reinforced concrete inner bracing beam to be used as blasting charge holes in the later stage of blasting. The influence of the hole on the mechanical behavior of the whole beam needs to be simulated by ABAQUS finite element software. In this paper, a beam in a group of beams with inner braces is taken as the research object. A model of a beam with holes is established in the software, and a fixed constraint is imposed on the end of the beam, and a uniform load is applied on the top of the beam. When the steel bar in the reinforced concrete beam reaches yield, the calculation is completed. The new load-bearing capacity of the model beam is determined by analyzing the load-displacement curve of the model beam.
【学位授予单位】：浙江海洋大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU746.5

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