What is Extended End-Plate Splice Joint? Explain in details step by step procedure to make a Extended End-Plate Splice Joint with example and application.
An extended end-plate splice joint, also known as an extended end-plate connection or moment-resisting connection, is a type of connection used to join two steel beams end-to-end. It provides continuity and strength to the structure by transferring bending moments between the beams. The extended end-plate connection involves bolting or welding an extended end plate to the ends of the beams, creating a moment-resisting joint. Here is a step-by-step procedure for making an extended end-plate splice joint:
Step 1: Design and Calculation
- Determine the loads and forces acting on the structure, including axial loads, shear forces, and bending moments.
- Calculate the required beam sizes, plate dimensions, and bolt sizes based on the applied loads, material properties, and design criteria.
- Determine the required number and arrangement of bolts for the connection.
Step 2: Preparation
- Gather the necessary materials, including the steel beams, end plates, bolts, nuts, and washers.
- Ensure that the surfaces to be welded or bolted are clean and free from rust, oil, paint, or any other contaminants.
- Prepare the welding equipment, such as welding machine, electrodes, and protective gear (e.g., welding helmet, gloves, etc.), or gather the necessary bolts, nuts, and washers for a bolted connection.
Step 3: Alignment and Fit-Up
- Position the steel beams in alignment with each other, ensuring proper orientation and contact between the ends.
- Use clamps or temporary tack welds to hold the beams in position during the connection process.
- Ensure that the ends of the beams are properly prepared, such as beveling or machining, to accommodate the end plates.
Step 4: End Plate Installation
- Place the end plates against the ends of the beams, ensuring proper alignment and fit.
- Mark the positions for bolt holes on the beams and end plates.
- Remove the end plates and drill the necessary bolt holes in the beams and end plates according to the marked positions.
Step 5: Bolted Connection
- Position the end plates against the ends of the beams, aligning the bolt holes.
- Insert bolts through the holes, placing washers and nuts on the opposite side of the end plates.
- Tighten the nuts using an appropriate torque wrench or other tightening method, ensuring proper tension in the bolts.
- Follow the recommended tightening sequence and torque values specified by the design standards.
Step 6: Welded Connection
- Tack weld the end plates to the beams to hold them in place.
- Double-check the alignment and dimensions before proceeding with the final welding.
- Weld the end plates to the beams using an appropriate welding technique, such as shielded metal arc welding (SMAW) or gas metal arc welding (GMAW).
- Ensure that the welds provide sufficient strength to resist the applied bending moments and shear forces.
Step 7: Quality Control
- Inspect the welds or bolts visually to ensure they are free from defects such as cracks, porosity, or incomplete penetration.
- Conduct non-destructive testing (NDT) techniques like ultrasonic testing or magnetic particle inspection to verify the integrity of the welds (if applicable).
- Verify the dimensions, alignment, and overall quality of the connection according to the design specifications.
Example and Application: Extended end-plate splice joints are commonly used in steel frame structures, such as multi-story buildings and bridges, where continuous beams are required to transfer bending moments. This type of connection is designed to provide stability, strength, and resistance to lateral loads.
For example, in a multi-story building, extended end-plate splice joints can be used to connect the beams of different levels, allowing for the transfer of bending moments between the beams. This provides continuity in the structural system, ensuring the overall stability and strength of the building.
It is essential to follow design codes, standards, and guidelines when designing and constructing extended end-plate splice joints to ensure the structural integrity and safety of the connection. The specific design and construction details may vary depending on the project requirements and the recommendations of structural engineers.