Chemical grouting is a grouting technique that transforms granular soils into sandstone-like masses, by permeation with a low viscosity grout. The soils best suited for this technique are sands with low fines content. Typically, a sleeve port pipe is first grouted into a predrilled hole. The grout is injected under pressure through the ports located along the length of the pipe. The grout permeates the soil and solidifies it into a sandstone-like mass. The grouted soil has increased strength and stiffness, and reduced permeability. Chemical grouting has been used to underpin existing foundations, create excavation support walls, create water cutoff walls and stabilize soils for tunneling.
For underpinning applications, chemical grouting offers the advantages of being easily performed where access and space is limited, and of not requiring a structural connection to the foundation being underpinned. A common application of chemical grouting is to provide both excavation support and underpinning when an excavation is planned immediately adjacent to an existing structure. Usually, chemical grouting can be accomplished without disrupting normal facility operations.
Chemical grouting equipment is well-suited for tunneling applications in urban environments, whether for stabilizing soil around break-ins or break-outs, or for mitigating settlement of overlying structures within the influence of the tunnel alignment.
Hayward Baker has developed proprietary special equipment and software (iGroutTM) to allow real time monitoring of all grouting parameters during the chemical grouting process. The operator can monitor the real time chemical grouting parameters, such as mix type, flow rate, pressure, and volume based on the real time signals from data acquisition hardware (transducers/flow meters) while simultaneously monitoring for any movements or deflections of the ground or nearby structures. Data collected during grouting is recorded on a database server which produces a grouting log for each injection location. Use of this advanced monitoring and control system helps to increase accuracy and efficiency, and reduces risk.
Contact your local Hayward Baker office for more information.