摘要
单层支撑基坑抗倾覆稳定性验算至关重要。在分析承压含水层对土体自重应力计算影响的基础上,得到承压水对基坑支护结构体内外两侧主动、被动土压力的计算模式,进而分析承压水对单层支撑基坑抗倾覆稳定性的影响。研究表明:承压水存在对单层支撑基坑抗倾覆稳定性产生不利影响,主要影响因素有:承压水水头、隔水顶板底部与基坑坑底距离和隔水顶板厚度。工程实践表明,可通过降压、坑底封底加固等措施有效降低承压水对基坑稳定性的影响,否则,会给基坑工程带来安全隐患,甚至造成基坑破坏。建议在基坑设计规范里验算基坑稳定性时应考虑承压水的作用。
The overturning stability check is very important in the single layer supporting structure for the deep excavations. The formula of quantifying the influence of the artesian groundwater on both sides of the supporting structure were deduced based on the influence of artesian groundwater on the overburden stress of above soils so that the effect of artesian groundwater on the stability of the single layer deep excavation structure can be evaluated. The results indicate that an adverse effect of the artesian groundwater on the stability of the supporting deep excavation structure could be concluded. Factors that might affect the stability are head of the artesian groundwater, distance between the bottom of aquitard soil layer to the bottom of deep excavation and the thickness of the aquitard. Throughout out the engineering practice, measures such as, lowering the groundwater head and improving the sealing at the bottom of the excavation can effectively reduce the effect of artesian groundwater on the stability the supporting structures. It is further suggested that the future design code should consider the effect of the artesian groundwater on the stability of the supporting structures for deep excavations.
作者
阳吉宝
YANG Jibao(Shanghai Municipal Engineering Design Institute(Group)Co.Ltd.,Shanghai 200092)
出处
《土工基础》
2020年第2期159-164,共6页
Soil Engineering and Foundation
关键词
单层支撑
基坑
承压水
抗倾覆稳定性
single-layer supporting structure
deep excavation
artesian groundwater
overturning stability
