杭州市钱江新城区承压水水位动态研究

Dynamic study on the confined water level in Hangzhou CBD

在深大基坑的开挖深度确定时,承压水水位的高低决定了承压水突涌风险的大小。研究承压水水位动态和趋势成为重要的课题。基于历史区域观测资料,结合近年来钱江新城区工程的不同观测频率的成果,进行统计分析、研究水位动态变化规律,并预测变化趋势。区内目前年平均水位介于-2^-3m,年水位波动约3m,4月份和6月份为高水位期,8月底~9月初是最低水位期。同一场地一定距离的不同点水位呈现"普遍不等,偶然相等"的现象。今后的一段时期内承压水水位将呈现稳中渐升的趋势。在无长期水位观测成果时,设计可以根据勘察所得水位,并按本文水位波动规律大致推测出基坑开挖期间的最危险水位,以确保基坑安全。

The confined water head determines the risk of confined water outburst flood for a certain depth of foundation pit excavation project. It is an important topic to study the dynamic and trend of confined water level. The dynamic rules of water level is researched and the level is predicted based on statistical analysis of the data collected from the area observation, combined with observation results of CBD project with different frequency in recent years. The trend of the water level is also predicted. The current water level annual average in the study area is between -2m -- -3m and fluctuates about 3m yearly. The high water level appears in April and June while the low level is from the end of August to early September. The water levels of different points departure for a certain distance in a same site arc different, the same occasionally. The confined water level will present a steady rising trend for a period of time in the future. In order to ensure the safety of foundation pit, if the long-term observation are absent, the most dangerous water level of foundation pit during the excavation could be roughly conjectured according to the water level in the instigation and the level variation rule in this article.