高寒地区水坠坝冬季施工技术试验研究

水坠筑坝是我国创造的一种快速、经济筑坝方法,但高寒地区冰冻期长,冲填施工受到季节限制。为此,青海省水科所等单位进行了水坠坝冬季施工技术研究。本文论述了高寒区冬季水坠筑坝施工技术试验成果,并应用热平衡原理对冲填泥浆的冻融与脱水固结规律进行了研究分析。试验研究表明,高寒区冬季水坠筑坝,边埂修筑采取“控温快速压实法”可以达到干容重1.69/cm~3的设计要求;昼冲夜停采取“浮冰法”可避免坝内形成冰夹层;间歇冲填采取打孔捅透泥浆冰结层的办法,在气温变暖和坝内泥浆热量传递下,厚约2m的冻结层十个月内可全部消融。据对坝体干容重、含水量、孔压、位移、沉陷等观测,坝内泥浆脱水固结正常,坝体稳定。试验坝已投入蓄水运用。

Experimental Study on Construction Technology of Hgdraulic Fill Dam in Winter in Cold Zone at High Latitude

Hydraulic fill dam is a fast and economic method for dam building,but the construction of filling is confined by seasons owing to long freezing period of cold zone at high latitude . therefore, the construction technology of hydraulic fill dam in winter in cold zone at high latitude has been studied by Qinghai Hydraulic Research Institute. In the paper ,the etperimental results of building hydraulic fill dam in winter in cold zone at high latitude are described and the laws of freezing-thawing and dehydration-consolidation are studied and analysed by using the principle of heat balance. It is shown through the experiments that the design criterion of dry unit weight 1. 6g/cm3 for building the edges of hydraulic fill dam in cold zone at high latitude can be achieved by "method of controlled temperature and fast compaction". And,also,"methed of floating ies "is adopted for fill during the day time and stop at night, avoiding forming ice layers in the dam ane ; the method of drilling through freezing layer is adopted for intermittent fill, the freezing layer of about 2m thick can be totally melted under the conditions of higher temperature and transmission of slurry heat in the dam. According to the observation of dry unit weight,moisture content,pore water pressure,displacement and settlement of the dam,dehydration-consolidation of the slurry in the dam is nurmal and the dam stable. At present, the experimental dam has been put into operation.