The essence of the method zalyuchaetsya that removing groundwater entering the well pit, the surface water in the soil becomes voronkoobrazoy, falling at the same time to the place of evacuation. The same effect is obtained when device drain groundwater. Foursquare is often quoted on this topic. When nipore groundwater funnel shape takes piezometric surface. Funnel-surface groundwater is called a depression surface, and drained space between the original (neponizhennoy) surface of an underground stream and a depression surface – a depression funnel. As the evacuation of the area of distribution and depth of a depression funnel increases. If the pumping rate remains constant, the time comes stabilization – steady state in which there is no further development of a depression cone. Upon the termination of pumping groundwater levels restored, and their surface (or piezometric surface) gradually acquires its original (natural) form.
Construction dewatering tasks in general are in the appropriate development and maintaining a reasonable period a depression funnel bearing sediments cut by foundation pit (construction), as well as in the removal of excess pressure in the underlying aquifer sediments, separated from the pit aquitard. In that case, if the depression surface water flow in the soil, cut ditches, anywhere it does not overlap, it is possible to dry all the underground construction, ie completely solved the main task of dewatering. Removing the head in the overlying layers is usually possible to implement within the prescribed limits, to avoid violation of the natural properties of base facilities. When construction dewatering used mainly temporary device, and the necessary equipment and facilities provided for the operation of facilities and enterprises, can be used temporarily for the duration of the construction. In this case vodoponizitelnye means and devices, along with the satisfaction of the conditions of the construction period must also comply with the relevant requirements of the project, which takes into account the conditions of their future operation. The collection is definitely located and designed to receive, pumping and draining groundwater in construction period devices and planned and carried out work on their construction, commissioning, operation and content of construction dewatering systems. Construction dewatering systems are formed with the use of drainage ditches and ditches of drainage, and open and vacuum vodoponizitelnyh wells well point and elektroosusheniya used in various combinations in the form of linear, ring, nepolnokoltsevyh, systematic, group and individual vodoponizitelnyh devices.