The indexes, such as the grouting volume in per unit area, grouting depth and 7d residual porosity, were proposed to verify the grouting ability of selected materials.
The longer the gel time, and the higher the pressure, the longer is the penetration length and hence the grouted volume is increased.
Through numerical modelling and thermal response testing, this study shows that a tight borehole heat exchanger could provide an acceptable thermal performance while optimizing the drilling and grouting volumes.
Based on a number of (empirical) relations from literature, such as the stability number method and an analysis of the bentonite and grout flows, volume loss at the face, along the shield and at the tail is determined.
To achieve efficient grouting the grouted silica sol volume must be optimized by taking account of the applied pressure and gel time.
Density measurement of the upper and the lower part of the grout's sheared volume in the rheometer were carried out at different characteristic times of the protocol and compared with rheological behavior of grout during shearing.
Grouting parameters include grouting time, pressure, volume, spreading radius, and borehole pattern, and all these parameters affect the grouting performance to some extent.
The volume of grout depends on the applied pressure.
In most cases, the volume of grout pumped is more than the volume of the hole.
In the grouting process, the selection of the physical forms of fly ash as grouting material is based on factors including grouting pressure, bed separation volume, and slant angle of the coal seam.
