基坑出水量计算方法探讨——“面井法”

基于平原区密集分布的农田供水井开采量评价方法——“面井法”,推导出了稳定流状态下,基坑出水量计算的一种新方法——“面井法”,并与“大井法”进行比较.“面井法”计算的基坑水位降深总大于“大井法”计算的基坑水位降深,而出水量则小于“大井法”计算的基坑出水量.“面井法”也定义了基坑等效半径,但形式唯一,简单易记.对于矩形(包括条形、方形)基坑,等效半径计算值总大于“大井法”计算值,而圆形基坑二者相等.由于“面井法”的推导是在整个基坑面积上积分的,其计算结果更能代表整个基坑的渗流特征.

Discussion of method in calculation water yield of foundation pit:areal-well method

On the basis of the exploitation evaluation method,"areal-well method" in the plains area where the farmland supply wells is densely distributed,The article develops a new method,"areal-well method" for calculation of the water yield in the foundation pit which is suitable for the steady groundwater flow.The method is compared with a large-diameter-well method.The conclusion is drawn that the drawdown suitable for calculated with the areal-well method is greater than with the large-diameter well method,but the water yield of the foundation pit is less than that with the large-diameter well method.In the areal-well method,an equivalent radius of the foundation pit is also with defined,and it has a sole format and is easy to remember.For the rectangular foundation pit including bar and square,the equivalent radius is always greater than that of the large-diameter-well method.For a circular foundation pit,the equivalent radius with both method is identical.Since the deduction of the areal-well method has been integrated on the whole foundation pit area,the calculated results can better represent the seepage characteristics of the whole foundation pit.