Over time, ground water can infiltrate brick and pre-cast manholes through open cracks, joints, and around pipe penetrations. This unexpected inflow of water can cause an increase in wastewater treatment costs, as well as infrastructure damage due to soil displacement surrounding the manhole structure. If the leak remains unsealed, the problem can result in sink holes, roadway collapse, and even backup of city sewage systems.
Among the possible plug and repair solutions, grout injection is the easiest, cheapest, and most effective. Grouts are pressure injected to the exterior of the structure. In addition grout is flexible and is not damaged or displaced by freeze/thaw cycles. Because of the application method, no excavation or structure replacement is required. Once catalyzed, grout becomes chemically inert and environmentally friendly. For these reasons, grout injection can be a cost-effective solution to a leaking manhole.
InfraEarth has two different approaches to leaks, crack injection and curtain grouting.
Crack Injection Grouting
When water is infiltrating through a focalized point, such as a crack or joint, our crew treat that specific area.
Step 1) Holes are drilled at specific angles into the center of the crack.
Step 2) Injection ports are inserted and sealed to the drilled hole.
Step 3) Grout is pressure-injected through the port and into the crack, where it reacts with the water and expands, forming a water proof seal at the surface of the leak and filling any voids that might be present behind the wall of the manhole structure.
In high-flow applications, specialized packing material is wedged into the crack to slow down the flow of water, giving the grout time to catalyze and seal the crack. Grout continues to be injected behind the crack to fill any washout voids.
