洞庭湖区蓄洪垸堤防加固工程水土保持措施与设计优化

Soil and water conservation engineering and design optimization advice for levee reinforcement project in Dongting Lake region

洞庭湖区地势平坦、土壤肥沃,现状水土流失强度轻微,但其堤防加固工程造成的水土流失影响仍不可忽视。总结了在堤防加固工程设计中,应重视的水土保持措施:包括土石方合理调配以尽量减少弃渣;选择合理的弃渣场,并因地制宜布置完善的拦挡、排水措施。同时,还从生态保护、节省投资角度,对主体护坡工程、堤基防渗工程提出优化设计建议,认为预制混凝土块护坡厚度应尽量切合实际,改变以往一直过于保守的状态;采用水泥土防渗墙进行堤基防渗,厚度可以减少为0.2 m。

There is flat terrain and fertile soil in Dongting Lake region and the present soil erosion intensity is slightly; however, the influence on local ecological environment caused by soil and water loss of levee reinforcement project should not be neglected. Some im- portant soil and water coriservation measures that shall be adopted in levee reinforcement project are summarized, which include rational distribution of earthwork resulting in reducing abandoned earthwork, and design dumping yards in proper locations with correct retaining and drainage measures. Meanwhile, advice on optimizing principal engineering designs are put forward from the perspectives of envi- ronmental-friendly and cost-saving, which concludes that the conservative design of using precast concrete block for slope protection should be changed, and the thickness of cement-soil cutoff wall for seepage control of levee foundation can be reduced to 20 cm.