Permeating grouting is accomplished by drilling holes in the soil and introducing injection pipes that pump in liquefied material into areas in need of reinforcement. It’s the oldest and most commonly employed type of grouting and the holes, injection pipes and material used are determined by the nature of the remediation of soil specifically needed. Permeating grouting is used primarily when encountering sandy soil conditions because such fine particulate matter allows the material injected to spread more rapidly over wide areas.
The most common type of permeation grouting is done with cement. When using cement grouting, Portland cement based grout is pumped into rock formations or soil. Any fractures in the rock formation as well as spaces or voids are filled. There are a myriad of specific uses such as when a concrete slab floor is tilting off center. In such instances a pipe for the grout could be installed under the lower leaning side of the slab. Once the grout is pumped under the slab it works in a similar manner as a hydraulic jack. The slab could then be raised with the grout to the level angle needed. Another example is injection of grout into rock formations for added stability before construction begins. This method can prevent foundation settlement due to grainy or other kinds of softer soil, fix sinkhole problems, repair fractures of machine bases and alleviate movement such as rocking under warehouse slabs.
Another fairly common type of permeation grouting technique to strengthen granulated soil conditions is chemical grouting. A chemical solution is injected into the ground facilitating bonding of granules into much stronger soils with higher load capacities. Base material is mixed with a hardening agent to create the chemical grout. The actual ingredient and mixing ratios are determined by the set time needed in any specific application. Water flow problems are usually addressed by the use of chemical grouting. Underground structures with leaking issues, such as tunnel support, pit excavation or types of below water construction are usually serviced by the use of chemical grouting techniques.