CSG坝筑坝材料特性与抗荷载能力研究

Charateristics and load carrying capacity of CSG dam construction materials

胶凝砂砾石坝(CSG)是介于混凝土面板堆石坝(CFRD)和碾压混凝土重力坝(RCC)之间的一种新坝型。其显著的特点是:胶凝材料用量少,对筑坝材料要求低,坝体和地基受力条件好,是一种环保性能、力学和大坝安全性能都很有竞争力的新筑坝技术。通过福建省龙岩白沙大坝、宁德洪口大坝的围堰以及尤溪街面大坝围堰等3个工程,对CSG坝的筑坝材料和抗荷载能力进行分析研究,并在街面工程的下游围堰进行局部CSG坝的工程实践。研究表明:CSG坝的水泥用量约为RCC重力坝的42.9%～49.1%左右,大坝断面可较CFRD坝减少100%,大坝位移量与RCC坝相当,而只有CFRD坝的1/20～1/10。不仅如此,CSG坝体受力条件明显改善,竣工期与运行期坝体内应力变化不大,大坝抗震能力明显增强。

Cement sand and gravel （CSG） dam is a new type of dam between concrete-faced rock-fill dam （CFRD） and roller compacted concrete dam （RCC） . It is obvious that the cement content is low and it is possible to utilize a wide range of materials. CSG is advantageous in environmental protection, internal stress feature and dam safety. The material characteristics and load carrying capacity are studied for the Baisha dam, the Hongkou dam and the Jiemian dam in Fujian province. These studies indicate that the unit cement content is 42.9-49.1 percent of the RCC＇s, and the dam section is one half of the CFRD＇s . The displacement of CSG is similar to the RCC＇s and is 1/10-1/20 of the CFRD＇s. In another aspect, CSG is superior in that the internal stress and the load on the foundation do not change significantly under full or empty reservoir conditions and the seismic resisting capacity of the dam is greatly enhanced.