某重点山洪沟防治措施及经济效益分析

气候、地形地貌、河流水系、人类活动是山洪沟致灾的重要因素。针对这些因素,需要有针对性地选择工程措施,采取不同的堤身断面型式,并注重堤脚抗冲刷设计。对于一般河岸,可采取造价较低的临水侧混凝土矮挡墙上接土质斜坡;对于迎流顶冲、深槽迫岸的局部危险堤段,可采取安全性更高的重力式混凝土挡墙;对于历史溃口段、堤身开裂段等险工险段,可采取堤身充填灌浆、临水侧混凝土挡墙护脚、生态护坡防冲等防治措施。为方便不幸落水者自救攀爬上岸,以及为动植物提供生长栖息环境,在挡墙临水侧增设混凝土凹槽,工程成本仅增加约3%。

Analysis on prevention measure for a key torrent gully and its economic benefit

Climate， topography， river system and human activities are the important factors for the disaster caused by torrent gully. In allusion to these factors， it is necessary to targetedly select engineering measures， adopt various dike section patterns and pay attention to the anti-erosion design of dike foot. For the normal river bank， the water-facing low concrete retaining-wall connected with earth slope with lower construction cost can be adopted； for the local dangerous flow-facing and scouring dike section with deep trough near bank， gravity concrete retaining-wall with higher safety may be adopted； for those dangerous sections， i.e. historical dike breach section， dike cracking section， etc.， the prevention measures such as dike filling grouting， foot protection for water-facing concrete retaining-wall， eco-slope protection and anti-scouring facility， etc. can be adopted. In order to facilitate the drowning person to climb ashore for self-rescue and provide growth and habitat environments for the relevant animals and plants， grooves is added on the water-facing side of retaining-wall， for which the construction cost is to be increased by only 3%.