Modified dapped end, precast prestressed double-tee slabs were considered in this research. It can facilitate insertion of service ducts at the dapped ends. The total depth of the floor slab may be reduced. In addition, the underside of the double-tee slab showed simpler appearance. Static three-point shear loading test was performed on full-scale specimens. And three modified single-tee slabs were analyzed by strut-tie model method. The specimen failed during the test in the same location as predicted by the strut-tie analytical model. The analysis of experimental results in comparison to the analysis results revealed that the experimental failure loads manifested 108% of analytical failure loads on the average.

Deep beam shall be designed either by taking into account nonlinear distribution of strain or by Appendix A of Strut-and-Tie Models (STM ) according to ACI 318(M ) from version of 2002. Although STM is accepted as tool in design Discontinuity region (D-region) which mostly exist in Deep beam, Corbels, Dapped ends etc., it has been modified by many researchers. In this study we design deep beam by STMs which use simple truss for load distribution and the model of complex truss for load distribution compare with the ACI traditional which is designed by flexure design method and shear provided by concrete(Vc) as provided in special provisions section of 11.8 in ACI 318-99 [1]. This study aims to find the different and efficiency of deep beam design based on variation of parameter compiled from many samples selected from ACI traditional and two model of STMs, simple and complex load distribution.

In this study, the strut-tie model used for the analysis and design of the anchorage zone of the PSC modular bridge by comparing with the result of the approximate analytical method. The result shows that the bursting force obtained by approximate analytical method were increased about 2 times in comparison with the result of strut-tie model.

To introduce how to design the shear wall for strut and tie model, and to secure the strength of shear wall by using Prestressing element, to control at working load condition. also to evaluate the performance of shear wall's capacity.