During the grouting reinforcement construction, ensure that the slurry adequately fills the soil pores by focusing on the following aspects:

Rational design of grouting parameters




Determine the Appropriate Grouting Pressure: Calculate and set the grouting pressure precisely based on the properties, depth, and purpose of the soil mass. Generally, for loosely compacted sand soil, the required grouting pressure is relatively low; however, for dense cohesive soil, higher pressure is needed. The appropriate pressure allows the grout to overcome the soil's resistance and smoothly enter the pores. For instance, in shallow sand soil, the grouting pressure may be controlled at 0.5-1MPa; while in deep cohesive soil, the pressure may need to be increased to 2-5MPa.

Controlling Grouting Speed: Excessive grouting speed can lead to insufficient penetration of the slurry, causing it to flow rapidly along channels with lower resistance, resulting in ineffective diffusion. On the other hand, a slower speed can impact construction efficiency and may cause the slurry to solidify and block the grouting pipes. The grouting speed should be adjusted reasonably based on the soil's absorption capacity and the performance of the grouting equipment. Initially, the speed can be slightly increased, but once the slurry starts to penetrate steadily, it should be reduced to ensure uniform filling of the pores.

Determine Grouting Quantity: By calculating the soil porosity, reinforcement range, and slurry diffusion radius, the grouting quantity can be accurately determined. Generally, the grouting quantity should be slightly higher than the theoretical calculated value to ensure the soil pores are fully filled. The grouting quantity can be estimated using the formula: where G is the grouting quantity, V is the volume of reinforced soil, ρ is the soil porosity, and k is the slurry filling coefficient (usually greater than 1).







Enhanced Slurry Performance




Adjusting Slurry Proportions: Select appropriate slurry materials and ratios based on the characteristics of the soil mass. For soil with larger pores, a fluid slurry with fine particles, such as cement slurry with a high water-cement ratio, can be used. For soil with smaller pores, it is necessary to increase the concentration and viscosity of the slurry, adding appropriate admixtures like bentonite and fly ash to enhance the filling capacity of the slurry.

Maintaining Slurry Setting Time: Properly control the setting time of slurry to ensure it maintains good fluidity during the pore-filling process and rapidly sets after completion to prevent slurry loss. For instance, by adding retardants or accelerators to cement slurry, adjust the setting time based on the specific conditions. In areas with high groundwater velocity, a cement-silicate double-liquid slurry can be used. By adjusting the ratio of the two liquids, the slurry sets within a short period, effectively filling the pores.







Choose the appropriate grouting equipment and technology.




Selecting Appropriate Grouting Equipment: Choose grouting equipment with good performance, stable pressure, and adjustable flow, based on the scale and requirements of the grouting project. Ensure that the grouting pump can provide sufficient pressure and flow to meet the grouting needs under different soil conditions. Additionally, regular maintenance and calibration of the equipment are essential to ensure its proper operation.

Utilizing Appropriate Grouting Techniques: Selecting the suitable grouting process based on soil properties and reinforcement requirements, such as infiltration grouting, crack grouting, or compaction grouting, etc. For soils with large pores and good permeability, infiltration grouting can be used; for dense soils, crack grouting or compaction grouting may be more effective. During the grouting process, methods like segmented grouting and repeated grouting can be employed to enhance the filling effect of the slurry.







Ensure Construction Quality




Precise Drilling Alignment: Drilling is strictly carried out according to design specifications to ensure the accuracy of the hole's location, depth, and angle. Detailed records should be kept during the drilling process to understand the stratification and promptly adjust drilling parameters. After drilling is complete, the hole walls must be cleaned to prevent collapse and debris from blocking the pores, which can affect grout penetration.

Ensure Quality of Grouting Pipe Installation: Accurately bury the grouting pipe to the designed depth, ensuring the pipe is tightly in contact with the soil mass to prevent leakage of slurry around the pipe. Sealant devices, such as rubber rings or cement slurry sealing, can be set on the outside of the grouting pipe to enhance the grouting effect.

Enhanced Construction Monitoring: During the grouting process, parameters such as grouting pressure, grouting volume, and ground deformation must be monitored in real-time. Promptly identify issues and take appropriate actions. If an abnormal increase or decrease in grouting pressure is detected, it may indicate soil pore blockage or grout leakage. Immediately halt the grouting, investigate the cause, and proceed with the necessary treatment.

By integrating these measures, we can effectively ensure that the slurry is fully filled into the soil pores during the compacted grouting reinforcement construction, enhancing the reinforcement effect.

Share

How to Choose Additives for Adjusting Slurry Performance?

How to Monitor the Diffusion of Slurry During Construction?

What types of projects are suitable for the compacted grouting reinforcement method?