汉江新集水电站土石坝水下抛填离心模型试验研究

Centrifugal model test study on underwater dumping-filling of earth-rock dam of XinjiHydropower Station on Hanjiang River

由于压实度的不可控性,水下抛填一直较少作为土石坝等永久建筑物的施工方案,而采取水下抛填可大大提高工程经济性,研究土石坝水下抛填施工技术具有重要意义。以汉江新集水电站主河床土石坝水下抛填施工为例,引入离心模型试验对其进行了前期论证,并在坝体填筑完成后通过超重型动力触探试验对水下抛填密度进行检测。结果表明:水下抛填密度与抛填料颗粒级配、上覆堆载、水深等因素密切相关,且经强夯处理后抛填体的有效加固深度在6.0 m范围内;离心模型试验和超重型动力触探检测成果相关性较好,可作为研究土石坝水下抛填密度的有效手段。研究成果给后续坝体设计、安全监测方案优化提供了数据支撑,对同类工程设计施工也具有重要参考价值。

Due to the uncontrollability of compactness,underwater dumping-filling has been less used as a construction scheme for permanent buildings such as earth-rock dams.However,underwater dumping-filling can greatly improve the engineering economy,so it is of great significance to study the underwater dumping-filling construction technology of earth-rock dams.Taking the underwater dumping-filling construction of the earth-rock dam on main riverbed of Xinji Hydropower Station on Hanjiang River as an example,a centrifugal model test was introduced for preliminary reasoning,and the underwater dumping-filling density was tested by super-heavy dynamic penetration test after the completion of the dam filling.The results showed that the underwater dumping-filling density was closely related to the particle gradation,overlying surcharge,water depth and other factors,and the effective reinforcement depth of the dumping-filling body after dynamic compaction was within the range of 6.0 m.The results of centrifugal model test and super-heavy dynamic penetration test have good correlation,which can be used as an effective means to study the underwater dumping-filling density of earth-rock dams.The research results can provide data support for the subsequent dam design and safety monitoring scheme optimization,and also have important reference value for the design and construction of similar projects.