山区河流轨道桥通航条件的影响分析

潘莉

重庆单轨交通工程有限责任公司，重庆  400084

摘要：为分析新建市郊铁路璧山至铜梁线小安溪桥航道的通航条件，建立工程河段平面二维水沙数学模型，与实测资料进行对比分析，论证最低通航水位和最高通航水位、通航尺度、桥梁通航影响分析等参数。论证结果表明：近年来桥区河段河床及河势基本稳定，河演分析表明桥位附近不会发生主槽易位、河床转型的状况，桥区河段河势、河床稳定；建桥后流场仅局限在桥位附近较小范围内变化，泥沙淤积和冲刷范围有限，不存在桥区河势条件改变的水动力和河床边界条件；建桥后桥区河段河床仍基本保持冲淤平衡状态，桥区河段的平面形态、深槽位置不会有较大变化，滩槽格局稳定，建桥未对桥址河段河势产生不利影响；设计航道最高通航水位为258.53 m，最低通航水位为255.01 m，通航净高为14.36 m，单孔单向通航净宽29.50 m，单孔双向通航净宽51.00 m，符合规范要求。

关键词：通航条件；山区河流轨道桥；通航净空尺度；通航水位

Influence analysis of navigation condition of track bridge over mountain river

PAN Li

Chongqing Monorail Transportation Engineering Co., Ltd.，Chongqing 400084，China

Abstract:In order to analyze the navigation condition of the Xiaoanxi Bridge waterway of the new suburban railway from Bishan to Tongliang line, a two-dimensional mathematical model of water and sediment in the engineering reach was established to analyze contrastively with measured data, and the parameters such as the lowest navigable water level and the highest navigable water level, the navigable dimensions, and the influence analysis of bridge navigability are demonstrated. The demonstration results show that, the river bed and river regime of the bridge reach are basically stable in recent years, and the river evolution analysis shows that there will be no main channel translocation or river bed transformation near the bridge location, and the river regime and riverbed of bridge are stable. After the construction of the bridge, the flow field limited to a small range around the bridge site is changed, and the range of sediment deposition and erosion is limited. There are no hydrodynamic and riverbed boundary conditions that change the river regime conditions in the bridge area. After the construction of the bridge, the riverbed of the bridge reach is still basically in a balanced state of scouring and silting, the plane shape and deep groove position of the bridge reach change slightly, and the shoal channel pattern is stable. The bridge construction has no adversely affected on the river regime of the bridge site. The highest navigable water level of the designed channel is 258.53 m, and the lowest navigable water level is 255.01 m, and the navigable clearance height is 14.36 m, and the single hole one-way navigable clear width is 29.50 m, and the single hole two-way navigable clear width is 51.00 m, which meet the specification requirements.

Keywords:navigation condition; mountain river track bridge; navigable clearance dimension; navigable water level