沉螺池的拦螺墙布置试验研究

 沉螺池是水利血防的一项重要工程措施，它是沉集和拦截水流中钉螺的建筑物，沉螺池内设置拦螺墙是近几年才实施的措施，作用在于提高拦螺效果。该措施实践时间不长，同时拦螺墙占了部分过水面积，水流通过此断面后流速较大，流态较复杂。为观察沉螺池中设置拦螺墙的阻螺效果及其对水流结构的影响并对其设计提出优化，进行了大量水槽试验。每次试验在不同的条件下进行，研究拦螺墙相对开度和断面平均流速等因素对沉螺池拦螺效果的影响，并分别试验了设置1道拦螺墙和2道拦螺墙的效果。试验表明：拦螺墙可以有效拦阻水面漂浮物，但是水流通过拦螺墙后流态会发生显著变化，在拦螺墙下游形成一定长度的回流区，长度与拦螺墙相对开度、水流流速等因素有关。挟带钉螺的水流通过拦螺墙后进入回流区，流态紊乱，流速增大，对钉螺的沉落造成困难。建议仅设置一道拦螺墙，并且应该设置在沉螺池上游尽量靠近进水口的地方。

Test Study on Layout of Wall Intercepting Snails in Settling Basin for Oncomelania Snails

The settling basin for oncomelania snails is an important project measure in water conservancy project in combination with schistosomiasis control,which is a sort of construction used to sink and collect oncomelania snails.The measure of setting wall intercepting oncomelania snails in the basin was adopted in recently years to enhance the settling effect.The intercepting wall occupies a part of the passing-water area,then the velocities will increase,and the flow conditions will become more complex.Objective of the paper is to study the intercepting wall's function and the effect to the flow structure.A great lot of tests were done under different conditions,including different opening degrees of the intercepting wall and setting one and two intercepting walls.Results show the intercepting wall can obstruct snails in the surface efficiently,but will change the flow.After passing the intercepting wall the water will take snails backwater region,the flow will be accelerated and become more turbulent,and will disturb the settling of the snails.So,it is suggested that only one intercepting wall should be settled near the inlet.