Precast Beam Splice (Beam to Beam Connection)

The connection: Why is it considered, what are the common issues and how is it verified.

Reasons why this type of connection is used.

• Off-site manufacturing for high level of quality.
• Constructability and speed of installation (curing period for connection is not required on site).
• Cost-saving as falsework is not required during construction.

Common problems encountered when designing this connection.

• Absence of programs with the capability to design such connections leading to time-consuming manual calculation.
• Guess-work in design assumption leading to conservative design.
• Design and code-check of anchoring not considering reinforcement which potentially lead to use oversized cross-sections.
• Modeling not according to actual condition.

Enter IDEA StatiCa connection. In this article, we will briefly illustrate how IDEA StatiCa Connection and Detail application can streamline the process of the designing the connection of precast beam splice as well as its anchoring for enhance efficiency and optimized design results.

Why use IDEA StatiCa

IDEA StatiCa connection application offers limitless capabilities for modeling intricate joint connections, and when combined with the Detail application, you will have a complete design tool that offers comprehensive solution for both steel and concrete design projects.

Modeling Strategy

By utilizing connection application, the approach to modeling this type of connection is to focus on one side of the joint where we will consider the precast beam to be represented by a concrete block. The other side of the precast, we will represent it with a steel beam just for the sole purpose of applying the loads (as it is not possible to apply loads into a concrete block in connection application in the current version of IDEA StatiCa). As the joint connection is symmetrical, the distribution of the internal forces as well as the stresses to the plates would be the same on the opposite side represented by steel beam.

Modeling of the Joint Connection
Modeling of the joint is done in connection application. Various analysis options can be carried out when using this application. In this example, stress-strain analysis can be used for code-check of the connection.

Start by adding the member and creating the splice connector through series of stiffening plates by welding each plate following the designed geometry.

Create the splice connector on the opposite side copying the same geometry for symmetry in modeling. Leave a gap of 8mm for tolerance during installation.

Model the concrete block to represent the precast beam. This can be done by using the manufacturing operation Grid and changing the fastener type to Anchor. Setup the anchors to its desired position. To use a shear lug, change the shear force transfer by selecting shear lug from the dropdown list.

Splice connector can now be joined by bolting together using manufacturing operation Grid and fastener option as Bolt. Provide 8mm shimming plates to fill the gap using manufacturing operation Stiffening plates.

Modeling is now complete. Apply load effects and run analysis by clicking on the Calculate toolbar icon.

Result summary can be viewed instantly as it is vividly displayed in the graphic window beside the model. Under check tab, end-users have the option to display the FE analysis results in the graphic window such as equivalent stress, plastic strain, stress in contacts, stress in concrete as wells as the bolt forces. In this illustration, the result for the anchor check is failing.

Export Connection to 3D Detail
To export the connection to 3D Detail for further verification of anchoring, click on RC Check. Note that the end-user must have a concrete license for this icon to be activated. 

Information such as loadings, concrete block size and strength, anchor sizes and geometry, plate detail are automatically captured inside the application once exported. End-users just have to define the support boundary condition as well as the required concrete cover.

Provide the required reinforcement
Use the Rebar Assembly toolbar to model the reinforcement. Multiple bars can be applied according to requirements.

Analysis can be performed with the consideration of concrete reinforcement. In this illustration, you see that the result for anchorage is now valid together with concrete and reinforcement.

Verification of results
Results can be reviewed and verified under Check tab. End-users have the option to display various code-check results for strength of concrete and reinforcement as well as anchorage. 

Equivalent Principal Stress

Stress ratio of reinforcement material

Bond stress ratio for reinforcement and anchors

Display deformed shape

Most importantly, structural report complete with detailed calculation and colorful visualization can be generated and is customizable to specific requirements which significantly assist when reviewed by authorities and/or checking agencies.

Summary

IDEA Statica is an essential tool for structural engineers due to its advanced capabilities in analyzing and designing connections and structural components with precision and efficiency. Its user-friendly interface streamlines complex tasks, allowing engineers to quickly generate accurate models and perform detailed calculations, which saves valuable time in project delivery.

_{Photo Source:}

^{Photo of precast concrete construction for inspiration of this modeling is captured from internet in courtesy to MASS Engineering Center. The modeling done here does not represent the actual usage and its reinforcement in the photo.}