植草型生态护岸水力特性试验研究  

Experimental research on hydraulic characteristics of eco-bank protection covered with grass

作　　者：钟春欣[1] 张玮[1] 

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210098

出　　处：《水利水电技术》2010年第10期22-25,40,共5页Water Resources and Hydropower Engineering

基　　金：水文水资源与水利工程科学国家重点实验室开放基金(2004405211)

摘　　要：为研究不同水流条件下植草型生态护岸上的植被表面曼宁糙率系数和Darcy-Weisbach阻力系数的变化规律,在室内大流速水槽内模拟河道径流对草皮护坡进行了冲刷模型试验。试验结果显示:(1)试验所选用的狗芽根(Cynodon dactylon)及高羊茅(Festuca arundinacea)的曼宁糙率值在0.025～0.090范围内;(2)植被表面曼宁糙率系数随流速的增大而减小,当流速超过4 m/s时,糙率值稳定在0.025～0.035之间,在某一稳定流量下,植被表面曼宁糙率值首先随冲刷历时的增加而递减,而后逐渐趋于稳定,并在护坡破坏时发生突增;(3)Darcy-Weisbach阻力系数不仅与植被的种类及生长状况有关,而且和植被的平均瞬时弯曲高度与水力半径的比值有关,随着水流流速及历时的增加阻力系数也随之减小。To study the varying rules of the Manning roughness coefficient and the Darcy-Weisbach friction factor of the eco-bank protection covered with grass under the different now conditions, a scouring model test is made in laboratory . to simulate the scouring from the river runoff on the grass covered bank protection with a flume of large flow velocity. The result shows that （ 1 ） the Manning roughness coefficients of both Cynodon dactylon and Festuea arundinaeea selected for the test are within a range of 0. 025 ~0. 090; （2） the Manning roughness coefficient of the vegetation surface is to be reduced along with the increase of the flow velocity and the roughness coefficient is to be kept between 0. 025 and 0. 035 when the flow velocity is over 4 m/s, under a stable flow rate, the roughness coefficient is to be decreased along with the increase of the scouring duration at first, and then goes to be stable gradually, furthermore, the roughness coefficient is to be suddenly increased, when the turf is destructed; （3） the Darcy-Weisbaeh friction factor is not only related to both the type of the vegetation and the growth status, but also related to the ratio between the transient bending height and the hydraulic radius, and then the resistance coefficient is to be reduced along with the increase of velocity and duration of flow.

关 键 词：草皮护坡 岸坡冲刷 曼宁糙率系数 Darcy-Weisbach阻力系数 试验研究 

分 类 号：TV143[水利工程—水力学及河流动力学]