速流结构防治泥石流的理论及应用

Theory and application of high-speed drainage structure in controlling debris flow

作为一种公路沿线发育的地质灾害,泥石流是路基、路面及相关建、构筑物最强烈的毁损动力。为了防治泥石流公路灾害,作者开发了速流结构。该结构由汇流槽和速流槽组成。其中汇流槽的侧墙长度、高度、厚度等参数通过泥石流沟形态及其冲击力综合确定;而速流槽的宽度、侧墙及纵横断面则由泥石流排泄量、流速、锁固桩及流体性质综合确定。根据公路穿越速流结构的方式,将速流结构分为底越式和顶越式2种。速流结构对于解决具有大冲大淤特性的冲淤变动型沟谷泥石流灾害具有重要应用价值。据此可以确保穿越泥石流沟的公路构、建筑物的安全与稳定,确保公路交通有序进行。此外,文章对速流结构的一些子结构,如速流槽侧墙及锁固桩进行了力学分析。位于川西南西昌-木里干线公路的平川泥石流属于典型的冲淤变动型沟谷泥石流。该沟长度8 2km,沟床平均比降0 181,平均流速9 0m s,沉积区宽度500m左右。为了确保该段公路交通的有序进行,作者于1999年实施了平川泥石流速流结构。通过2000年以来的研究及现场测试,显示了该防治结构的优越性。但是,作为一种特殊的水工结构,泥石流对速流结构的磨蚀作用是比较强烈的。因此,开展速流结构的抗冲、抗撞研究是进一步研究具有重要价值。

As one of geologic disasters along highway,debris flow is the strongest dynamic force to destroy roadbase,road surface and other relative structures.Based on the research on debris flow in highway the authors develop High-speed Drainage Structure(HDS) in order to control debris flow in this paper.HDS is composed of converge trough and high speed drainage trough.Further parameters such as length,height and thickness of lateral wall of converge trough are identified at least by debris flow valley and impact force while the width,lateral wall and longitudinal and section concavity of high speed drainage trough are ensured by discharge,velocity,anchor pile and fluid features of debris flow.According to mode of HDS passing highway the authors divide HDS into both top-pass HDS and base-pass HDS.HDS is quite applicable to drain mass of valley shape debris flow with erosion and deposit,which ensures the safe and steady of highway structures to pass the debris flow valley so as to make highway traffic in order.It is founded that there are some mechanical methods for substructures of HDS such as lateral wall of converge trough and anchor pile high speed drainage trough in the paper.Pingchuan gully,locating at the highway from Xichang to Muli in Southwestern Sichuan Province,is one of typical valley shaped debris flows with erosion and deposit.Valley length of the debris flow is 8\^2km while the normal gradient and the normal velocity are 0\^181 and 9\^0m/s respectively.Deposit area width of the debris flow is 500m.In order to ensure the traffic the authors put HDS into effect in deposit area in 1999.Through investigation and in-situ tests since year 2000 the effect is quite obvious.However as one special hydraulic engineering structure,abrasion of HDS is strong so it is valuable to research anti-abrasion and anti-impact for HDS under action of debris flow in the future.