基于拦截比的边坡虹吸排水孔几何参数研究

发布时间：2018-12-16 17:48

【摘要】：滑坡是一种常见的地质灾害,它常常给经济建设和人们的生命财产安全带来严重的损失。地表水和地下水的活动是导致滑坡灾害发生的重要因素之一,90%左右的边坡破坏都发生在雨季。坡体内地下水位抬高后,土质受到软化,粘聚力及抗剪强度降低、增大的孔隙水压力将使坡体的抗滑力下降,容易导致滑坡灾害的发生。及时有效地拦截地表水入渗并排除地下水,对于防止滑坡灾害的发生,提高边坡稳定性起着至关重要的作用。虹吸排水是一种免动力实时排水措施,它的原理是把排水管通过下倾斜孔进入边坡的深部,并从斜孔的孔底引出虹吸排水管到坡面一定位置,在坡体内部水位上升时,利用虹吸管两端的进出水口高差实现实时排水。虹吸排水可以免动力实现水体的高效跨越输送,通过改变边坡地下水位线的形状和分布,提高边坡的稳定性,是一种新型有效的边坡排水方法。在实际工程中需要通过合理布置虹吸排水孔群来显著降低地下水位从而较大程度的增加边坡的稳定性。已有的地下水动力学对于竖直井群孔排水有较为系统的认识,但对于倾斜式的边坡虹吸排水缺乏适用性。将井群孔降水与倾斜排水的排水效率相结合,引入排水拦截比的概念,由地下水向潜水完整井稳定流动的浸润曲线方程,推导排水拦截比与群孔间距的关系式,得到不同的排水孔布设间距对虹吸排水效果的影响。在实际计算中可以根据工程要求确定排水拦截比并求出相应的井孔间距,为实际工程的设计提供相关依据。构建边坡物理试验模型,研究排水孔倾斜角度对排水效果的影响,试验结果表明地下水位以下部分孔长与排水拦截比呈线性关系;实际工程中当控制地下水位降深相同,通过改变排水孔的倾斜角度来增大地下水位以下部分孔长能有效增强虹吸管的排水效果;试验结果验证了文章理论推导部分的准确性。
[Abstract]:Landslide is a common geological hazard, which often brings serious losses to economic construction and people's life and property safety. The activity of surface water and groundwater is one of the important factors leading to landslide disasters. About 90% of slope failure occurs in the rainy season. When the groundwater level in the slope is raised, the soil will be softened, the cohesion and shear strength will be decreased, and the increase of pore water pressure will reduce the landslide resistance of the slope body, which will easily lead to the occurrence of landslide disaster. Timely and effectively intercepting surface water infiltration and removing groundwater play an important role in preventing landslide disasters and improving slope stability. Siphon drainage is a kind of non-dynamic real-time drainage measure. Its principle is to enter the drain pipe into the deep part of the slope through the downward sloping hole, and to draw the siphon drainage pipe to a certain position on the slope surface from the bottom of the hole of the inclined hole, and when the water level inside the slope is rising, Real-time drainage is realized by using the water inlet and outlet height difference at both ends of siphon. Siphon drainage is a new and effective method for slope drainage by changing the shape and distribution of underground water level and improving slope stability. In practical engineering, siphon drainage holes should be arranged reasonably to reduce the groundwater level significantly, thus increasing the slope stability to a large extent. There is a systematic understanding of groundwater dynamics for vertical hole drainage, but it is not suitable for slope siphon drainage. Combining the drainage efficiency of well group with slant drainage, the concept of drainage interception ratio is introduced, the infiltration curve equation of steady flow from groundwater to complete well is derived, and the relationship between drainage interception ratio and group hole spacing is deduced. The influence of different spacing of drainage holes on siphon drainage effect is obtained. In the actual calculation, the drainage interception ratio can be determined according to the engineering requirements and the corresponding well spacing can be calculated, which provides the relevant basis for the actual engineering design. The physical test model of slope is constructed to study the influence of inclined angle of drainage hole on drainage effect. The experimental results show that the length of the hole below the groundwater level is linearly related to the drainage interception ratio. In practical engineering, when the depth of underground water level is the same, increasing the length of the hole below the groundwater level by changing the inclined angle of the drainage hole can effectively enhance the drainage effect of the siphon pipe, and the experimental results verify the accuracy of the theoretical deduction part of the paper.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22

【参考文献】