Pavement Reinforcement Over Weak Sand at Israel Shipyards

Neoloy® Geocells were selected for pavement reinforcement at Israel Shipyards, where severe cracking and deterioration was evident.

The asphalt pavements of the large working platform docks at the Israel Shipyards suffered severe cracking and deterioration. These are caused by voids in the sand subgrade (which fill the dock’s steel frame) as a result of the saturated marine conditions. Heavy loading from the shipyard’s 400 ton cranes, heavy machinery and container-loaded trucks combined with inadequate structural reinforcement caused failure of the platform surface and substructure layers.

The entire structural pavement needed to be replaced with a solution offering durable reinforcement over the unstable subgrade with sufficient bearing capacity for the entire range of shipyard activities. The shipyard was interested in fast and cost-efficient construction methods to reduce operational downtime and work backlogs.

Rehabilitation of Intermodal Working Platform, Israel Shipyards israel-shipyards-sub1

Rehabilitation of Intermodal Working Platform, Israel Shipyards

Conventional Approach

The conventional approach was a 35 cm reinforced concrete pavement structure strong enough to form a bridge over the soft subgrade. This would have required not only large amounts of concrete and steel, but large quantities of high quality aggregate for a 30 cm subbase as well. The estimated construction time and costs involved in such a structure were considerable.

Neoloy Geocell Solution

The Neoloy Geocell confinement system was chosen for the wharf rehabilitation for its engineering advantages (load bearing and distribution, reduced settlement) and long-term design strength. The entire pavement structure was first removed due to excessive damage. Then 20 cm of Neoloy Geocell infilled with local sand was installed over the geotextile and compacted sand subgrade. 100% infill compaction was certified by Nuclear Gauge and GeoGauge devices. Above the Neoloy, a 12 cm granular subbase layer and a well-graded 20 cm aggregate layer stabilized with 5% cement were installed. The surface layer was comprised of 10 cm standard concrete paving blocks on a 3 cm compacted sand leveling course.

Client benefits

  • Fast installation
  • Increased load bearing and distribution meets shipyard’s requirements
  • Semi-rigid mattress reduces differential settlement thereby minimizing degradation
  • Excellent drainage and durability in saturated conditions best suited for marine platform
  • Use of local sand for structural infill
  • Long term durable life-span
  • Cost-effective