高水位下的大长宽比沉井的施工控制及受力和变形的研究

发布时间：2018-05-28 22:39

本文选题：沉井 + 高水位　；参考：《天津大学》2014年硕士论文

【摘要】：随着工业规模的迅速扩大化,工业设备基础也呈现大型化的趋势,我们在施工中不可避免的遇到较深的水池及设备基础,如果在施工场地附近,地下水位较高,通常在工程中会运用沉井的施工方法,有时采用沉井还进行水下封底,以上是基于确定基础的施工质量和进度。作为一种基础结构,沉井相当于是上部荷载传递的载体,最终由地基承担。首先,通过凌钢十二五结构调整技术改造公辅项目翻车机室沉井制作工程,详细介绍了在高水位下的大长宽比沉井从设计、制作到施工的整个过程,包括工程背景,设计思路,沉井的制作、施工降排水、沉井下沉系数及抗浮验算、沉井的施工等主要步骤。在施工中发现了枕木抽取困难的现象,只有少量的枕木完整的抽出。对沉井的施工以及在其过程中所可能出现的问题进行分析和研究,得出了沉井施工中的容易出现的问题和有效控制和处理方法,得出了在以后的施工中采用无枕木施工法,根据预制沉井的重量,增加刃脚下砂垫层的厚度,分层夯实,在刃脚与砂垫层之间浇筑砼垫层。下沉前用大锤、风镐等将砼垫层破碎,即可挖土下沉的建议。为高水位下的大长宽比沉井的施工提供了合理的施工方案和有效的控制方法。其次,通过PLAXIS有限元软件,模拟了大长宽比沉井的井壁土压力和变形特点,通过计算发现:沉井具有很强的空间效应,井壁在边角处侧向位移较小,在中央处侧向位移最大,整体呈“踢脚”的变形状态;沉井长边的侧向位移远远大于短边的侧向位移,长边的侧向位移更应该加以重视,必要时需要设置隔墙,以达到减小位移的目的。本文通过实际工程和有限元模拟,给出了高水位下的大长宽比沉井的设计和施工的建议,为实际工程提供了参考。
[Abstract]:With the rapid expansion of industrial scale, the industrial equipment foundation also presents the trend of large-scale, we inevitably encounter deeper pool and equipment foundation in the construction, if the underground water level is higher near the construction site, The caisson construction method is usually used in engineering, and sometimes the caisson is used to seal the bottom underwater. The above is based on determining the construction quality and schedule of the foundation. As a foundation structure, the caisson is equivalent to the upper load transfer carrier, which is ultimately borne by the foundation. First of all, through the engineering of the sinking well in the overturning chamber of the 12th Five-Year structural Adjustment Technical Transformation Project of Linggang, the whole process from design, manufacture to construction of the caisson with large aspect ratio under high water level is introduced in detail, including the engineering background and design ideas. The main steps such as the production of caisson, drainage, sinking coefficient and anti-floating checking calculation, construction of caisson, etc. In construction, the phenomenon of difficult extraction of sleepers is found, and only a small number of sleepers are extracted completely. Based on the analysis and study of the construction of caisson and the problems that may appear in the process of caisson construction, the easy problems in caisson construction and the effective control and treatment methods are obtained, and the non-sleeper construction method is adopted in the later construction. According to the weight of prefabricated caisson, the thickness of sand cushion at the foot of the blade is increased, the layer is rammed and the concrete cushion is placed between the blade foot and the sand cushion. Before sinking, the concrete cushion can be broken with hammer and pick. It provides a reasonable construction scheme and effective control method for the construction of the caisson with large aspect ratio under high water level. Secondly, the characteristics of borehole wall earth pressure and deformation of caisson with large aspect ratio are simulated by PLAXIS finite element software. Through calculation, it is found that the caisson has strong spatial effect, the lateral displacement of shaft wall is smaller at the edge corner and the maximum lateral displacement is at the center. The lateral displacement of the long side of the caisson is far greater than that of the short side, and the lateral displacement of the long side should be paid more attention to, and the partition wall should be set up when necessary to reduce the displacement. Through practical engineering and finite element simulation, this paper gives some suggestions for the design and construction of large aspect ratio caisson under high water level, which provides a reference for practical engineering.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU753.64

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