Over the years of heavy use, the pavement, base and sub-base beneath the Port of Oakland’s gantry crane wheel paths had started to subside. Ground subsidence is very common in situations as this, cyclical loading and heavy loading conditions, especially when the loads have increased over the years. The differential settlement not only made it difficult for the operators to align their cargo properly, but also created a safety hazard while the cranes traveled amongst the site. The settlement ranged anywhere from a 1/2″ up to 4″ at the worst case.
Port of Oakland Chooses EagleLIFT
When it comes time for Port Engineers to evaluate the different repair processes for their pavement maintenance and rehabilitation, numerous factors must be considered. Factors such as down time to the end client, company qualifications, company experience and services being offered.
Once these factors were taken into account, only one contractor met the criteria: EagleLIFT, Inc.
Solutions and Results
Prior to any injections taking place, EagleLIFT conducted a series of Dynamic Cone Penetration (DCP) tests to measure the relative soil density. The DCP tests indicated that the sub-base needed to be densified at the -2.5′ depth.
Deep Injection was then utilized to densify those soils and lift the pavement to grade. The two-part polymer material is injected through 1/2″ tubes which are driven down to depth through the pavement. The resulting mixture polymerizes beneath the slab, creating minimal heat with optimum expansion. With this expansion, the material aggressively seeks out voids filling them while densifying surrounding soils and lifting the pavement back to its original elevation eliminating the settlement.
This Port’s proactive approach and willingness to embrace new technology allowed EagleLIFT to work with Port officials and Engineers to address the settlement issues and possible solutions for it. This particular project exhibited the greatest problem to the client since closing the aisles, removing the pavement and replacing it would not only be costly, but also highly disruptive to Port operations.
This method was chosen for the following reasons. First, laboratory testing of the material used, proved it maintains its integrity for more than 10 years with no shrinkage or degradation. Recent studies of other one-part grouts found that conventional grouts are significantly impacted by the factor of time and “wet/dry” cycles. This unique method is quick, eliminates the need for removal and re-pouring as well as dramatically decreasing the disturbance to normal use if this area. Resins injected cure within 15 minutes allowing full use to be restored almost immediately after the work was completed.