Growth of economic, demographic and building activities in Iraq has necessitated carrying out geotechnical investigations for soft soils to study behavior of foundation resting on these soils. The laboratory test has been carried out to analyze the effect of tire as reinforcement to decrease the excessive settlement of soft soil. The influence of depth and area of tire layer is examined on the settlement of shallow foundation. For this purpose, a square foundation (60 *60) mm is used for the model test. All tests are conducted on the surface of homogeneous soil layer 250 mm; in a box steel (600 x 300 x 300) mm. The undrained shear strength of soil is 12 kPa. The reinforcement layer (tire layer) has been placed at depth 0.5B, B and 2B (B is the width of the square foundation) in the soft soil under foundation. The area of tire layer (B x B), (1.5B x 1.5B) and (2B x 2B) are investigated too. The analysis of the test results indicated that using tire layer under foundation has a significant effect on the settlement improvement (St/Su). It is worth noting, that the settlement improvement (St/Su) is decreased with the increase of the depth of tire layer. The results shows that the maximum increase in bearing capacity reaches approximately to 130% at area of tire layer (B x B) and depth equal to 0.5B.

In this study, the stresses around a tunnel during construction stages are discussed. For this purpose, the finite element method (FEM) was adopted as an effective approach to analyze the problem using (SIGMA/W) program.The research includes the study of the behavior of soil due to excavation of tunnel by calculating the displacements and stresses in three positions of tunnel (crown, wall, and invert) during the various stages of construction.The finite element analyses were carried out using (Elastic-plastic) and (linear elastic) models for the soil and the concrete liner respectively. From the results, it can be noticed that increasing the number of excavation stages (using six stages) decreases the displacement comparing with excavation using one stage.

Reactive powder concrete (RPC) possesses superior structural and mechanical characteristics. Despite these excellent properties, the main drawback of RPC is that it is a very costly material. This study included an experimental program for studying the flexural behavior of hybrid beams containing RPC together with self-compacting concrete (SCC) in the same section. Five specimens with dimensions of 100 x 150 x 1000 mm were investigated. The first crack load, ultimate load, maximum deflection, load-deflection response, and crack pattern were investigated. The experimental program included testing five reinforced concrete beams with four-point loading. The specimens were cast as follows: full depth of self-compacting concrete; full depth of reactive powder concrete; half of the section depth of RPC (tension zone); quarter of the section depth of RPC (tension zone); and half of the section depth of RPC (compression zone). The experimental results of the hybrid beams showed that using RPC in the tension zone of the beam significantly improved the performance of the hybrid beams when compared with the SCC beam. The improvement rate increased with the RPC layer thickness in the tension zone. Using RPC in the compression zone together with SCC did not produce a significant improvement in the performance of the hybrid beams.