Quantitative Calculation of Crustal Deformation Induced by Incomplete Penetrating Well Drainage in Confined Aquifers Without Leakage Water Complement

The crustal deformation induced by groundwater drainage is a sort of important atectonic deformation, by which there is significance in studying dynamic geodetic surveying in high precision, tectonic deformation and variation of station coordinates in the Coventional Terrestrial Reference System with millimeter precision. It is very hard, however, to calculate accurately the deformation due to groundwater drainage. Based on Segall's work the authors have derived the integral analytic expressions with groundwater drawdown, for surface vertical and horizontal displacement due to a well withdrawal of groundwater permeable flow in radial direction. And the authors make use of these expressions to compute quantitative displacement caused by a single well drainage in steady and non-steady groundwater flow in several canonical strata. According to the researches mentioned above, drainage wells are all complete penetrating ones, and incomplete wells are not discusssed. As we all know, permeable features of confined unfull penetrating wells are different from those of confined full wells. The confined unfull well is about three-dimensional flow, but the latter is about two dimensional flow. It is the three-dimensional flow that makes us meet more complex problems when computing crustal deformation caused by the drainage of groundwater for an unfull well. With some hypothese, the authors have made quantitative calculation of crustal deformation induced by the drainage of an incomplete penetrating well in confined aquifers without complement of leakage water. The corresponding formula has been given and the concrete schemes have been also discussed. At last the numerical integration programs have been made in line with Hermite integral formula with 20 nodal points. The examples, of course, in this paper show that the way explained here is effective.