The current study involves placing 135 boreholes drilled to a depth of 10 m below the existing ground level. Three standard penetration tests (SPT) are performed at depths of 1.5, 6, and 9.5 m for each borehole. To produce thematic maps with coordinates and depths for the bearing capacity variation of the soil, a numerical analysis was conducted using MATLAB software. Despite several-order interpolation polynomials being used to estimate the bearing capacity of soil, the first-order polynomial was the best among the other trials due to its simplicity and fast calculations. Additionally, the root mean squared error (RMSE) was almost the same for the all of the tried models. The results of the study can be summarized by the production of thematic maps showing the variation of the bearing capacity of the soil over the whole area of Al-Basrah city correlated with several depths. The bearing capacity of soil obtained from the suggested first-order polynomial matches well with those calculated from the results of SPTs with a deviation of ±30% at a 95% confidence interval.

Sand dunes are spread in multiple places in the world especially in a desert area as a result of economic development and construction processes, there was a need to study the behavior of sand dunes and make it suitable for construction. This paper aims to study the effect of adding sodium silicate on the cohesion strength of sand dune and its behavior. The results show that the cohesion strength increase as a percentage of sodium silicate increase (addition 8% Sodium silicate show the higher cohesion) and the cohesion between sand dune particles increase excepted when using 10% sodium silicate the cohesion began to decrease. However, the effect of curing time is significant and shows that as the curing time increases the cohesion strength of sand dune increases.

In the well point construction process, it is necessary to control underground water effectively. The expected damage pattern scope within the influence radius of the depression cone of the well point can be determined according to noticeable ground and building settlement, as well as reference to the soil property changes due to the dewatering process with the aid of the formation mechanisms of underground water, based on underground water flow theory. This paper examines the Damage Pattern Scope expectation (DPS) and discusses some underground water conditions and practical key points by means of examining a laboratory pilot-scale model with light well point water lowering of different soil strata thickness, thus analysing the impact on the surrounding environment due to water lowering. The results showed that the water content and the void ratio of soil subjected to dewatering were reduced and that soil density and cohesion thus increases.