what are launch and reception pits?
Left: Sheet Pile and Steel Waler Shoring as a Launch Pit.
Launch and reception pits are critical structures used in trenchless pipe installation methods, such as pipe jacking and micro-tunnelling. The launch pit houses the jacking frame and pipe segments, while the reception pit allows for retrieval of the tunnel boring machine or cutter head.
Right: Sheet Piles and Hydraulic Bracing used as Launch Pit Shoring.
Designing a launch or reception pit is not just a matter of digging a hole and shoring it up — it’s a complex structural engineering challenge. The design must account for:
Soil and groundwater pressures
Equipment and surcharge loads
Adjacent structures
Hydraulic thrust forces during jacking
Safety factors under worst-case conditions
Size of launch equipment and rig orientation
Left: Trench Box Designed as a Launch Pit
These factors are assessed through detailed geotechnical investigations and incorporated into a fully engineered temporary works design, typically signed off by a CPEng-qualified structural engineer.
Effective design requires close collaboration between geotechnical and structural engineers. While the geotechnical engineer determines ground conditions and soil parameters, the structural engineer uses this data to:
Calculate lateral earth pressures
Design shoring boxes, bracing frames, walers, and sheet piles
Validate structural safety under all load combinations
Prepare temporary works drawings and certification
At Enshore, we understand the importance of value engineering launch and reception pits to ensure tenders are cost effective as well as being buildable when its time to mobilize.
Enshore produce launch and reception pit shoring designs which specify equipment from every supplier in the Australian market and consider structural steel alternatives. We support our clients by obtaining materials pricing, conducting availability assessments and costing exercises to Enshore tenders remain sharp and the shoring can be procured and installed with buildability in mind.
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