防城港核电厂复杂沉积岩地基稳定性评价

目前国内开工兴建的核电厂均选用沿海各向同性火成岩作为地基。而广西沿海火成岩仅占1.6%,作为广西首个获准建设的防城港核电厂,其地层在广西具有代表性,为志留系沉积岩,岩性复杂、软硬相间,次生褶皱、断裂和裂隙发育,对于核电厂建设是巨大的挑战。本次勘察通过大量的地质测绘,充分论证了建筑场地的稳定性;根据深入的钻孔岩性统计和相关的物理力学试验结果分析,对地基岩土体进行工程地质归纳、分层,将其归纳为:粉砂岩组、泥质粉砂岩组和泥页岩组,有效地解决了场地岩性和空间组合复杂的问题;利用加权平均的方法获得的三个岩组的地基承载力,充分考虑了岩组中不同岩性的空间组合特征和其力学贡献,更真实的反映了岩组的力学特性;并通过当量模量和地基沉降量的计算,确定核岛地基是均匀的。近期,核岛基坑的开挖直接证实了勘察成果的准确性。

The Stability Evaluation of the Complex Sedimentary Foundation in Fangchenggang Nuclear Power Plant

Now the domestic nuclear power plants which have been started build are isotropic igneous rock foundation at coastal area.The igneous rock at Guangxi coastal area is only 1.6%.The stratum of Fangchenggang nuclear is representative and which is complex lithology,soft and hard alternated,having more fracture etc.it is a great challenge to the nuclear power plant construction.This investigation discussed the stability of the building site by detailed geologic mapping and made engineering geology division to three petrofabrices as siltstone,argillaceous siltstone and shale by the statistics of strata and test data.The complexity of rock was considered in foundation bearing capacity by weighted average method and the homogeneity of nuclear island foundation was proved by the calculation of equivalent modulus and settlement.All these was proved by the excavation of nuclear island foundation pit.