Level Crossing Removal Project

Paper

Pdf Summary

The Level Crossing Removal Project – Package 1 removed three crossings on Melbourne’s Frankston Line at Ormond, McKinnon and Bentleigh. It replaced about 2.5 km of at-grade railway with three cuttings, up to 8 m deep and 25 m wide, retained by approximately 4 km of piled walls. Around 250,000 m³ of soil had to be excavated during a tightly constrained 10-day rail occupation in densely populated suburbs.<br /><br />Key geotechnical challenges included retaining-wall stability, restricted construction access, groundwater control, and providing a stable subgrade for heavy construction plant. Sheet piles and continuous flight auger piles were used for the walls. In narrow spaces near homes, a Giken Silent Piler installed sheet piles with substantially less noise and vibration than conventional methods.<br /><br />At McKinnon and Bentleigh, cuttings extended below the water table. Conventional deep wells and wellpoints proved unsuitable, so four horizontal directionally drilled (HDD) wells were installed to dewater the corridor. The system performed well at Bentleigh, enabling excavation with conventional equipment. At McKinnon, silting reduced its effectiveness; contingency measures, including sump pumping and ground improvement, allowed works to finish without significant delay.<br /><br />Where base slabs lay below the permanent water table, screw piles were used to resist hydrostatic uplift and cyclic train loading. Tests on three piles under 20 uplift-load cycles showed that most accumulated movement occurred within 15 cycles, supporting the design assumptions.<br /><br />The project demonstrated how specialist piling, HDD dewatering and robust contingency planning can address geotechnical constraints in confined urban rail works. It also highlighted the importance of matching well filters to the ground conditions, monitoring groundwater pressures, and identifying procurement lead times early.

Keywords

Level Crossing Removal Project

Frankston Line

geotechnical challenges

piled walls

sheet piles

horizontal directional drilling

groundwater control

screw piles

retaining wall stability

urban rail excavation