振冲法在土坝除险加固工程中的应用研究

Application research on vibroflotation method in soil dam reinforcement project

用振冲法加固土石坝具有效果可靠、施工方便、工期短等优点。结合云南下口坝水库除险加固工程,对除险加固方案、施工技术、加固效果等进行了系统分析。实践证明:振冲碎石桩起到了抗滑桩、排水砂井和垫层3方面的作用;在淤泥质土层中施工时,需采取碎石固壁、增大孔径等方法确保成柱质量。经振冲法加固后,下口水库大坝土体和坝基土的标贯击数平均提高了38%和50%。

Earth and soil dam reinforcement project by vibroflotation method has advantages such as reliable effects, conven- ient construction and short construction period. Combining with danger removal and reinforcement project for Xiakou Reservoir in Yunnan Province, a systematic analysis on reinforcement scheme, construction technology and reinforcement effects are conduc- ted. It is pointed out that vibro - replacement stone pile plays three roles in the construction, namely, anti - slide pile, sand well and cushion; in clay stratum, piles quality must be ensured by gravel wall and increasing borehole diameter. After reinforcement by vibrofloatation method, SPT blow count of filling soil of Xiakou Dam is increased by 37% in average, and 50% for foundation soil.