The Initial Design for Roller Compacted Concrete (RCC) Gravity Dam of a Water-control Project in Cold Area

摘要

The some key water-control project in Xinjiang is made up of main dam (RCC gravity dam), auxiliary dam (1# and 2# clay core dam), water release structure (crest outlet, middle and bottom outlet), water intake structures for power generation (water-intake type ground plant in the right bank, water inlet tower, one high-pressure pipeline, bifurcated pipe) and power plant. The main features and technical difficulties are as follows: (1) Adverse weather condition in dam site area. Hot in summer, cold in winter, the annual temperature difference (average temperature difference between the highest and the lowest is 67. 5°C, extremely 89. 9°C) and daily temperature difference (average 12. 8 - 16. 2°C) are very large. The evaporatation is strong, normal evaporation is as much as 10 times of the average precipitation. The average wind speed is 1. 8m/s, with the maximum wind speed being 25m/s. The project is located in dry and cold region, cold, hot, wind, dry weather is very extrusive, so the problem of concrete temperature control is extremely prominent; (2) the groundwater is erosive. From No. 35 to No. 39 dam section, pyrite distribution on cracks surface is relatively concentrated. Particularly in No. 37 dam section, pyrite oxidation belt depth is larger; (3) The concrete aggregate is Gneiss granite artificial aggregate mixed with natural sand, this kind of concrete aggregate mixture scheme has no engineering example.