STEP is a tool developed to aid engineers with implementing the strut-and-tie method for the design of bridge substructure components. The engineer should be familiar with the limitations and the assumptions of the program prior to using it as a design tool.

An integral abutment need not be designed by the strut and tie model if the longitudinal reinforcement is determined by conventional beam analysis in BDM Article 11.6.1.3 and a minimum orthogonal grid of reinforcing bars is provided in accordance with the following table.

Dec 19, 2006 · Crack control can be verified using provisions of 10.6.4, assuming that the tie is encased in a prism of concrete corresponding to the area of tie (RA.4.2). There are usually several STMs that can be devised for a given structural member and loading condition. Models that satisfy the serviceability requirements the best have struts and

crack control. For example, in cases where 0.2% reinforcement was used as crack-control reinforcement, the width of the diagonal cracks exceeded 0.016 in. when they first formed and crack width increased with additional loading. To model the spread of compression in a diagonal strut (Fig. 2), let us consider the direct and indirect load

Dec 1, 2023 · Strut-and-tie model (STM), with its truss analogy, is yet a powerful tool for analyzing and designing complex prestressed and reinforced concrete structures. Which represents a simplistic method that predominantly provides conservative strength predictions.

The crack control reinforcement required when using AASHTO LRFD strut-and-tie provisions is much greater than that needed for strength purposes in a bottle-shaped strut. A direct strut mechanism (as shown in Figure 2) forms for beams in which the shear span-to-depth ratio is less than 2. The use of ACI 318-05 strut-and-tie specifications also

Oct 12, 2016 · Strut-and-tie models (STM) are trusses consisting of struts, ties and nodes. STM Replace stress paths with polygons of forces to provide equilibrium. Conventionally, struts are drawn as dashed lines, ties as full lines and nodes numbered. What is strut and tie? Eurocode 2 gives guidance for each of these. What is Strut and Tie?

These include the use of 3D strut-and-tie models for designing drill shaft footings under eccentric axial loads, the use of curved-bar nodes in closing knee joints, the provision of appropriate confnement to enhance nodal strength, and the relaxation of the “d/4 limit” on crack control reinforcement spacing based on experimental data.

In 2014, STM provisions were moved into the main body of the code as Chapter 23, Strut-and-Tie Method. This document focuses on the ACI 318-19 implementation of strut-and-tie modeling.

It has been recently understood that the strut and tie method (STM) is an effective tool for the design of both B and D regions. The present code recommendations are inadequate for the design of deep beams. In this paper simple equations using STM are developed for finding the area of main steel required to have.