Design of Deep Beam Using Strut-and-Tie Method A Case Study of Pile Cap

Abstract

This study takes a look at modeling of deep beam using strut-and-tie method using pile cap as a case study. There are B and D region in the deep beam (B standing for beam or Bernoulli and D standing for discontinuity or disturbance). A deep beam has a span-depth, a/d ratio ranging from 2.0 to 2.5. Thereafter, the strut-and-tie modeling (STM) of pile cap was displayed. The STM was later used to obtain the forces in a case study. These forces are important for the design of the pile cap. The design of the pile cap was carried out using various codes – ACI 318-08 (American Concrete Institute), E.C. 2 (Eurocode 2)-(using STM) and BS 8110 (British Standard)-(using flexural method). The differences and similarities between the results obtained using the 3 codes were reviewed with ACI 318-08 providing higher quantity of reinforcement than the other two codes. A percentage difference of 15.92 and 15.88 for tension and compression bars respectively was obtained from the comparison of ACI 318-08 and EC2 respectively. Also, a percentage difference of 50.05 and 16.07 for tension and compression bars respectively was obtained from the comparison of ACI 318-08 and BS8110 respectively. In addition, a percentage difference of –3.90 and –22.22 was obtained for C-C-T and C-T-T nodes respectively when comparing ACI 318-08 and EC2. In all comparison, ACI 318-08 was used as the base point.