水对滑坡支护结构工作参数的影响

发布时间：2017-12-28 20:18

本文关键词：水对滑坡支护结构工作参数的影响　出处：《西安工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：山洪、泥石流、滑坡、崩塌是陕南秦巴山区最为常见的几种自然灾害形式。近年来极端气候频现和人类活动范围的拓展造成了人们常常要直面滑坡等灾害带来的巨大威胁。降雨和地下水作用下的水影响因素是引发滑坡的重要条件这已经成为学者共识,水作用下的滑坡灾害发生时间短,范围大,往往难以预测,动态水环境下对滑坡加固的抗滑桩近年来被越来越多的应用于灾害防治和边坡治理工程中。近年来微型桩作为一种特殊的抗滑桩因其施工效率高、成本经济、应用范围广,作用效果明显,对坡体的扰动较小。布桩形式及其破坏模式对实际工程有着重要的指导意义。本论文先简要介绍了松散堆积层的形成和特点、降雨环境下导致滑坡发生的条件及微型桩受力特点,后通过在仿真模型箱中实施人工降雨和下伏岩层注水,通过试验模拟三种雨强情况下和一种模拟地下水作用在软弱层的情况下对微型桩的工作参数影响。试验中三排模拟桩互相平行,错位排列,排间设置连系梁,锚固深度为2/5L(L为桩身长度),桩的间距为10D(D为桩身直径),采用逐步加载的方式进行荷载作用。模拟水环境试验表明:1.土和含水率与荷载作用下桩身的位移正相关,在含水率6%--22%的松散堆积层支护结构中,土体的含水率越高,相同荷载下产生的滑坡位移就越大,且在此范围内,抗滑桩的整体工作性能都比较稳定。2.在使用1000mL/min的较强的降雨强度的条件下,松散的土体急剧失陷,强度降低,土体吸水后向内塌陷收缩,形成各种裂隙。当堆积层土壤的桩土共同作用区含水率达到17%左右时,上部滑体的整体性就可能已经遭到破坏,滑体受力方式从最初的倾倒前伏状态变成为断裂拉裂状态,这个状态会形成先减轻压力后突然增大压力的冲击特点,对支护结构的破坏作用尤其严重。3.降雨对于桩身弯矩有增大作用,降雨作用下锚固端所受弯矩最大值一般可以达到其抗滑端最大值的3到4倍,地下水容易导致锚固端的土体发生软化,导致整个滑坡位移增加,抗滑段在位移过程中倾角增大,最终容易导致桩工作用区土体松化与桩身脱离。因此地下水的存在对于支护结构也存在不利影响。
[Abstract]:Mountain torrents, debris flows, landslides and landslides are the most common forms of natural disasters in the Qinba mountain area of Southern Shaanxi. In recent years, the frequency of extreme weather and the range of human development make people often have to face a huge threat to landslide disasters. The factors affecting water under rainfall and groundwater is an important condition for the landslide has become a consensus, the landslide disaster occurred in a short time under the action of water, large range, often difficult to predict the landslide reinforcement of anti slide pile in recent years has been applied more and more in disaster prevention and control engineering of slope under dynamic water environment. In recent years, as a special anti slide pile, micro pile is of high construction efficiency, cost economy, wide application range and obvious effect, and the disturbance to the slope is small. The form of pile and its failure mode have important guiding significance for practical engineering. This paper briefly introduces the formation and characteristics of loose accumulation, resulting in the occurrence of landslide under rainfall conditions and micro pile stress characteristics, through the implementation of artificial rainfall and underlying strata water simulation model in the box, by simulating three kinds of rain intensity case and a simulated groundwater effect work parameters of the micro pile in the soft layer. In the test, three rows of simulated piles are parallel to each other. They are arranged in a misaligned way. The connecting beams are arranged between rows. The anchorage depth is 2/5L (L is the length of pile body), and the spacing between piles is 10D (D is the diameter of pile body). Loading is carried out step by step. Show that the water environment simulation test: 1. soil moisture content and the displacement and load of pile body is related to the moisture content in the loose 6%--22% stack supporting structure, the soil moisture content is higher, displacement of landslide under the same load is greater, and in this range, the overall performance of anti slide pile are relatively stable. 2. in the use of 1000mL/min's strong rainfall intensity conditions, reduce loose soil sharp fall, intensity, soil water after the collapse inwards contraction, forming various cracks. When the accumulation of soil pile soil interaction zone moisture content reaches about 17%, the whole of the upper sliding body may have been destroyed, the sliding body force from the initial state into v before dumping fracture crack state, this state will form the impact characteristics of the first to relieve the pressure suddenly increased after pressure, particularly serious the destroying effect of retaining structure. 3. rainfall increases for the pile bending moment, the effect of rainfall under the fixed end bending moment of maximum can reach 3 to 4 times the maximum value of the sliding end, easily lead to groundwater soil anchor end softening occurs leading to the landslide displacement increases, anti sliding section increases the angle in the process of displacement, eventually lead to effect of soil pile and pile out of pine. Therefore, the existence of groundwater has adverse effects on the support structure.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22;TU753.3

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