Optimization of parameter values for deep well dewatering in deep foundation pits on the Yangtze River class Ⅰ terrace based on effective control of pumping volume and ground settlement
This article focuses on the current deep well dewatering in deep foundation pits which only focu-ses on the target depth reduction and corresponding ground settlement without considering the effective control of pumping volume under the condition of meeting the target depth reduction conditions.Taking the Wuhan Yangtze River Tunnel open cut section deep well dewatering project as an example,through pumping tests,the influence of the diameter of the well pipe,the relative position b/M of the inlet section,and the degree of incompleteness l/M of the well on the inflow volume of the foundation pit were analyzed.The dewatering parameters such as the length of the water stop curtain,the diameter of the well pipe,the effective length and reasonable position of filter tube were determined and an empirical formula for the in-flow of partially penetrating wells in the region was fitted based on the experimental data.A parameter op-timization design model for deep well dewatering of deep foundation pits was established to control pum-ping volume and ground settlement.The length of the filter tube obtained by solving Maxf(l)is similar to the pumping test results.The research results show that when the waterproof curtain enters the strong permeable layer with a thickness of 2/3,it has a controlling effect on the pumping volume inside the foun-dation pit and the water level inside and outside the pit.When Φ250 well pipes and filter pipes are installed in the upper part of the strong permeable layer(b=0),with small l/M values and a difference in additional resistance coefficient difference(ξ1-ξ2)at maximum,the water inflow of the foundation pit is relatively small.The length range of the filter tube corresponding to the point with the highest curvature in curve q0-l、△q0/△l-l is 14.0 m to 16.0 m,and its corresponding excavation water inflow q0 is the smallest.Con-sidering the influence of group well interference,the water inflow of the interference well is the smallest at the center of the foundation pit and the largest at the corner.
deep well dewatering of deep foundation pitcontrol of pumping volumeground settlementwa-terproof curtainfilter tube lengthgroup well interference
万方数据
维普
