小桥涵自由式出流冲刷试验  

Freedom outlet scour test of bridge and culvert

作　　者：沈波[1] 艾翠玲[2] 田伟平[1] 徐岳[1] 

机构地区：[1]长安大学特殊地区公路工程教育部重点实验室 [2]福州大学土木工程学院,福建福州350002

出　　处：《长安大学学报（自然科学版）》2007年第3期61-66,共6页Journal of Chang’an University(Natural Science Edition)

基　　金：国家西部交通建设科技项目(200131881234)

摘　　要：公路水灾调查表明,山区公路小桥涵自由式出流出口水毁频率较高,为了明确其水毁机理,进行了小桥涵自由式出流模型冲刷试验。试验结果表明:端墙进、出口小桥涵后自由式出流垂裙处最大冲刷深度及冲刷坑最大冲刷深度是由出口单宽流量与铺砌长度共同作用的结果,当出口单宽流量相同、出口铺砌长度小于水流水跃前的扩散长度时,垂裙处最大及平均冲刷深度随着铺砌长度增加而增加,但铺砌长度越短,冲刷断面与冲刷深度分布变差系数越大;一般冲刷坑最大深度越大,最大冲刷点越靠近垂裙处;在同等条件下,端墙远大于八字翼墙、进出口的垂裙处及冲刷坑最大冲刷深度;端墙进、出口与八字翼墙进、出口冲刷坑冲刷深度发展过程基本一致,所不同的是端墙进、出口冲刷坑中间部位存在回淤变化过程,端墙进、出口垂裙最大冲刷深度靠近两侧岸,八字翼墙进、出口垂裙最大冲刷深度相对在中间部位。The mountainous highway water damage research indicates that the bridge and culvert freedom outlet scour damage has high frequencies. In order to decrease its outlet flow damages, the model tests of the freedom outlet scouring were carried out. The test results show that： the droop skirt location and the scouring hole＇s eroding maximal depth are determined by outlet per unit width runoff and paving length for regular entrance; as pavement length smaller than the fore length of hydraulic jump the droop skirt location eroding maximal and average depth is becoming larger along with pavement length increasing, but as the pavement length is becoming shorter, the scouring cross section deepness branch variation coefficient is becoming larger; on the same conditions, the droop skirt location＇s and scouring hole＇s eroding maximal depth of scouring maximal depth is larger, the maximal scouring depth point is nearer to the droop skirt the erode depth growing course of the regular entrance conforms with sidelong entrance outranee outlet lappet eroding stage, but the regular entrance outlet droop skirt location eroding maximal depth point is nearing both side of the bank, and the regular entrance outlet droop skirt scour process exists some deposits, sidelong entrance outlet lappet eroding maximal depth point is at the middle of the groove. 8 tabs, 2 figs, 8 refs.

关 键 词：桥梁工程 小桥涵 自由式出流 冲刷深度 试验 

分 类 号：U44[建筑科学—桥梁与隧道工程]