Copyright © 2018 Authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Engineering & Technology, 7 (4.20) (2018) 251-258 International Journal of Engineering & Technology Website: www.sciencepubco.com/index.php/IJET Research paper Applying Various Types of Loading on Continuous Deep Beams Using Strut and Tie Modelling Khattab Saleem Abdul-Razzaq 1 *, Ali Mustafa Jalil 2 , Abbas H. Mohammed 3 1 University of Diyala, Civil Engineering, Diyala, Iraq 2 University of Diyala, Civil Engineering, Diyala, Iraq 3 University of Diyala, Civil Engineering, Diyala, Iraq *Corresponding author E-mail: dr.khattabsaleem@yahoo.com Abstract This work aims at presenting detailed procedures companied by numerical examples for designing reinforced concrete two span continuous deep beams under various types of loading; one concentrated force, two concentrated forces and uniform load for each span. Analysis and design was conducted based on Strut and Tie modeling (STM) of ACI 318M-14 since they contain significant extents of D-regions and they show a marked truss or tied arch action. It was found that changing the loading type has a significant impact on the capacity for the same specimen that has the same dimensions, concrete and steel properties, in addition to the same amount and arrangement of steel reinforcement. In more detail, the increase in the number of concentrated forces causes an obvious increase in ultimate capacity due to the reduction in span to overall height (a/h) ratio and the increase in the value of the strut-tie angle, which causes shortening in the length of the strut. Therefore, the ultimate capacity increased by about (44-70) % when the applied load was changed from 1-concentrated force to 2-concentrated forces or to uniformly distributed load. Keywords: Reinforced concrete, Continuous deep beams, Strut and Tie, one and two concentrated forces, Uniform load, Design procedures. 1. Introduction Deep beams are loaded on one face and supported on the opposite face such that strut-like compression elements can develop between the loads and supports and that satisfies (a) or (b) [1]: (a) Clear span ln does not exceed four times the overall member depth h. (b) Concentrated loads exist within a distance 2h from the face of the support. Many investigators have suggested empirical and semi- empirical expressions to determine the ultimate load capacity of conventionally reinforced concrete deep beams [2, 3]. Some researchers studied the parameters that affect deep beams such as effect of heating, existence of openings, strengthening of openings, amount and type of web reinforcement, types of loading, concrete and steel strengths [4-10]. Furthermore, Abdul-Razzaq and Jebur suggested alternatives for reinforced concrete deep beams by reinforcing struts and ties only as compressive and tensile members, respectively [11]. Since 2002, the ACI- 318 Code procedure is based on empirical equations for the design of deep beams. According to ACI 318M-14 [1], STM is defined as "a truss model of a structural member or of a D- region in such a member, made up of struts and ties connected at nodes, capable of transferring the factored loads to the supports or to adjacent B-regions". Provisions for STM have been also taken into considerations by many authors for the design purposes. STM complies with the plasticity lower bound theory, which needs that only yield conditions in addition to equilibrium to be satisfied. Plasticity lower bound theory states that if the load has such a value that it is possible to find a distribution of stress corresponding to stresses that keep internal and external equilibrium within the yield surface, then this load will not cause failure of the body. In other words, the capacity of a structure as estimated by a lower bound theory will be less than or equal to the real failure load of the body in question [12]. 2. STM Analysis and Design Procedure An emerging methodology for the design of all types of D-Regions is to predict and design an internal truss. This truss is consisting of steel tension ties and concrete compressive struts that are interconnected at nodes, to support the imposed loading through the regions of discontinuity. The STM design procedure includes the general steps summarized below [1]: i. Define the D-Region boundaries and determine the imposed sectional and local forces. ii. Draw the internal supporting truss, find equivalent loadings, and calculate the truss member forces. iii. Choose the reinforcing steel to provide the necessary capacity of the tie and ensure that this tie reinforcement is adequately anchored in the nodal zones. iv. Evaluate the dimensions of the nodes and struts, such that the capacities of these components are adequate to carry the values of the design forces. v. Select the distributed reinforcement to guarantee the ductile behavior of the D-Regions. It is important to note that both hydrostatic and non-hydrostatic nodes are idealizations of reality. The use of either hydrostatic or non-hydrostatic nodes is an assumption that a design tool intended to provide a simple method for proportioning STM. The classical method of node dimensioning is by node shape arranging so that the applied stresses on all sides of the node are equal. The stress biaxial