Water-logging is defined as the state of land in which the subsoilwater table is located at or near the surface with the result that theyield of crops commonly grown on it is reduced for the land, or if theland is not cultivated, it cannot be put to its normal use because of thehigh water table. Water-logging is serious problem in Egypt, becausethe land subjected to water logging results in reduction of agriculturalproduction. The main objectives of this study are:1- Study the effect of soil layer depth to impermeable layer, and soiltypes on water logging in agricultural lands.2- Study the effect of irrigation systems, and crop types on waterlogging.vertical pre-stressing force.The purpose of this research is to study the behaviour of the pre-stressedconcrete flat slab - column connections using both bonded and unbondedmulti-strand tendons of full-scale factory floor under the designed servicelive loads. The studied slabs have three bays of 12 meters span by six baysof 6 meters span.This study offers proposed equation for prediction the punching shearresistance of column- slab connection from physical analytical model, thattaking the integration of the vertical component of concrete tensile strength,the dowel forces of supplementary bonded reinforcement and the pre-stressing force from pre-compression and vertical component of pre-stressing calculated by yield line theory.The comparisons of the present proposed equation with ECP 203, ACI 318,BS8810, and EC2 code provisions and Gardner equations for the presentexperimental study and scaled studies reported in the literature whichindicated that the equation is less conservative.Finally from the proposed equation the contribution of concrete tensileforce, dowel force and pre-stressing force in the punching shear resistanceof pre-stressed concrete flat slabs can be calculated.