复杂河流漫滩公路防护设施选型设计研究

Study on Selection and Design of Highway Protection Facilities for Complex River Floodplain

在河漫滩修建公路代替部分桥梁能有效降低工程造价,提高建设资金效能,但在河漫滩建设垂直于河流方向的公路会对河道行洪产生影响,为了兼顾跨河公路工程与河道行洪安全,同时有效降低工程造价,有必要对拟建工程防护设施选型进行优化。以某复杂水文、地质河流中河漫滩拟建公路为例,首先根据漫滩公路对河道行洪、泥沙淤积的影响,设计了不同类型的防护设施;然后对比分析了不同防护设施性能及造价、工期,选择了较好的导流坝方案进行优化设计,消除其不利因素的影响,以达到行洪安全的目的。结果表明:在宽浅型河槽合理利用河漫滩修筑公路替代桥梁,对降低工程造价有显著效果,能有效解决边远山区交通设施建设资金不足的问题,助力乡村振兴战略的实施。河流漫滩公路防护设施采用导流坝方式,并结合漫滩形状采用“人”字形,与洪水河势有较好的互适性,相对控制主流摆动,对河道行洪及泥沙淤积的影响最小,同时造价适中,并且优化设计后拟建工程对河流没有产生新的不利影响,这种多角度的综合研究方法可以为类似工程提供参考。为进一步减小防护工程对防洪等方面的不利影响,俟机大范围推广拦沙缓冲保路工程技术是必要的。

Building a road instead of a part of the bridge in the vast floodplain can effectively reduce the project cost and improve the efficien⁃cy of construction funds,but the construction of a road perpendicular to the river direction in the floodplain will inevitably have an impact on the river flood flow.In order to take into account the safety of the cross⁃river highway project and river flood flow,and effectively reduce the project cost,it is necessary to optimize the selection of protective facilities for the proposed project.This paper took the proposed highway in the flood plain of a complex hydrologic and geological river as an example.Firstly,according to the impact of floodplain highway on river flood flow and sediment deposition,different types of protection facilities were designed.Then,the performance,cost and duration of differ⁃ent protective facilities were compared and analyzed,and a better diversion dam scheme was selected for optimal design to eliminate the ad⁃verse factors,so as to achieve the purpose of flood safety.The results show that the rational use of floodplain to build roads instead of bridges in wide and shallow river channels has a significant effect on reducing project cost,and can effectively solve the issue of insufficient funds for the construction of transportation facilities in remote mountainous areas,and help the implementation of rural revitalization strategy.The pro⁃tection facilities of river floodplain highway adopt diversion dam mode and combine with the hermenez⁃shape of floodplain,which has good compatibility with river regime of flood,can relatively control mainstream swing,has minimal impact on river flood and sediment,the cost is moderate and the proposed project after optimization design has no new adverse impact on the river.This multi⁃angle comprehensive research method can provide reference for similar projects.In order to further reduce the adverse effects of protection engineering on flood control,it is necessary to extend the technology of buffer and road protection engineering to a large scale.