Research on the water level of anti-floating of building structure based on long-term boreholes and rainfall observations

This paper studies anti-floating groundwater level of main body structure foundation pit, with a case study of the metro line 2 at Sanqiao station, Guiyang. The relationship between long-term groundwater level monitoring data and rainfall data was analyzed. On this basis, a method for the calculation of anti-uplift water level values was put forward. Main result shows that,(1) anti-uplift water value consists of three parts, i.e. the highest groundwater level during the site investigation, the groundwater level rise by unexpected recharge and the maximum groundwater fluctuation rate compared to that of the site exploration period; (2) The groundwater levels monitored fluctuate seasonally which commonly increase in rainy season and decline in dry season, with the highest water levels appear in June and July; (3) The linear relationship between the change of the groundwater level and the change of monthly rainfall was obtained by the linear fitting of the rainfall in April, May and June; (4) Combined with the historical rainfall, the maximum increase of the groundwater level in the field area is 2.26 m, and the anti-floating water level in the field area is 1,128.46 m.