微型桩加固堆积层膨胀土滑坡模型试验研究

发布时间：2019-03-12 11:56

【摘要】：一直以来人们尝试用多种手段对滑坡工程进行防治,其中绝大多数是利用传统的抗滑桩、混凝土框架梁、挡土墙等方式。随着灾害防治技术的发展,微型桩以其经济性和良好的加固效果,越来越多的在浅层堆积层滑坡治理中应用。“5.12”地震以后,陕南地区特殊的堆积层膨胀土滑坡防治引起了工程界和学术界的关注。在灾害治理中,微型桩加固堆积层膨胀土滑坡得到了较多应用并取得了良好的效果和经济效益。当前诸多学者对堆积层滑坡及其微型桩加固机理进行研究取得了一些成就,推动了微型桩技术的发展,但对微型桩加固膨胀土堆积层滑坡机理研究文献甚少,尚未形成一套成熟的加固技术规范,制约了微型桩技术的推广和应用,所以对微型桩加固堆积层膨胀土滑坡机理研究并提出相应的设计原则和设计体系有着重要的理论和实践意义。模型试验是研究微型桩和加固技术的一条重要途径。试验以相似理论为基础,在一个1200mm×1200mm×1000mm的框架中进行。利用从陕南地区勉县毛家沟村实际工程中采集的膨胀土为模型材料制作滑体,进行了模型试验。通过自制的喷淋装置和烘干装置模拟自然界的降雨和蒸发,并对坡顶进行均布加载。试验过程中以桩间距、桩排距、锚固深度、连系梁等为变量,以不同的研究目的分6组进行。通过预先埋设的土压力盒、应变片和位移传感器进行实时量测,得到20000多组不同工况、不同位置、不同时间阶段的数据。对试验数据处理分析后得到以下主要结论：桩间距以(8～10)d(d为桩径)为宜；排间距以(5-10)d为宜；锚固深度D以L/3≤D≤2L/5(L为桩长)为宜；最佳土拱效应时,桩间距为(8-10)d。本文通过模型试验对微型桩进行了一系列的研究,分析了微型桩加固堆积层膨胀土机理并提出了若干微型桩设计原则,对微型桩加固膨胀土堆积层滑坡研究和技术应用方面发挥了重要的推动作用。由于论文工作时间和技术手段的限制,在材料相似性和传感器使用和数据采集上仍存在着不足和缺陷,未来的研究工作中应加以改进。
[Abstract]:People have been trying to use a variety of methods to prevent and control landslide engineering, most of them are using traditional anti-slide pile, concrete frame beam, retaining wall and so on. With the development of disaster prevention and control technology, with its economic efficiency and good reinforcement effect, micro-piles are more and more used in the treatment of shallow layer landslides. After the "5.12" earthquake, The special landslide prevention and control of expansive soil in the south of Shaanxi province has attracted the attention of the engineering and academic circles. In the disaster treatment, the expansive soil landslide strengthened by micro-piles has been widely used, and good results and economic benefits have been obtained. At present, many scholars have made some achievements in studying the mechanism of accumulation landslide and its micro-pile reinforcement, which has promoted the development of micro-pile technology, but there are few literatures on the mechanism of micro-pile-reinforced expansive soil accumulation landslide. It has not yet formed a set of mature reinforcement technical specifications, which has restricted the popularization and application of micro-pile technology. Therefore, it is of great theoretical and practical significance to study the mechanism of expansive soil landslide strengthened by micro-pile and put forward the corresponding design principle and design system. Model test is an important way to study micro-pile and reinforcement technology. Based on the similarity theory, the experiment was carried out in a framework of 1200mm 脳 1200mm 脳 1000mm. Using expansive soil collected from the actual project of Maojiagou village in Mian County, southern Shaanxi Province, as a model material, the model test was carried out. The rainfall and evaporation of nature were simulated by self-made sprinkler and drying device, and the top of slope was loaded evenly. During the test, pile spacing, pile row distance, anchoring depth and tie-in beam were used as variables, and were divided into six groups according to different research purposes. More than 20000 groups of data of different working conditions, different positions and different time stages were obtained by real-time measurement of pre-embedded earth pressure boxes, strain gauges and displacement sensors. The main conclusions are as follows: pile spacing (8 / 10) d (d as pile diameter), row spacing (5 / 10) d, anchoring depth D (L / 3 / D / 2 L / 5 (L = length of pile) are suitable for pile spacing, (5 / 10) d for pile spacing and (5 / 10) d for row spacing, and L / 3 / D / 2 L / 5 (L for pile length), respectively. When the soil arch effect is the best, the pile spacing is (8? 10) d. In this paper, a series of research on micro-pile is carried out through model test, and the mechanism of micro-pile strengthening pile with expansive soil is analyzed, and some design principles of micro-pile are put forward. It plays an important role in the research and technical application of micro-pile strengthening expansive soil accumulation landslide. Due to the limitation of working time and technical means, there are still some deficiencies and defects in material similarity, sensor use and data acquisition, which should be improved in the future research work.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU443;TU753.8

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