Ground improvement scheme
For tunnel construction and excavation soil in the shield section, we also conduct detailed test analysis and scheme of slag improvement.
The shield tunnel of a project in Chengdu mainly passes through <2-9-3> dense pebble soil (Q4al) and <3-8-3> dense pebble soil (Q3al+pl), and the rest are filled with medium-fine sand.
On-site slag sample
The purpose of our experiment and the improvement plan are to adjust the fluidity, water resistance and flow plasticity of the slag.
Use a thermogravimetric analyzer to test the moisture content of the muck sample:
Restore the natural moisture content of the slag to ensure that the slag sample experimented is consistent with the one on-site.
Take a small sample of the slag, and initially formulate the appropriate ratio of foam and bentonite from various adaptation effects to achieve the best fluidity of the slag.
The effect of each foam and bentonite ratio
After selecting the ratio, we use the stirring torque meter to test the experimental data, and record the torque of the stirring tool and the slump of the slag.
During the test, the torque meter displays:
The red torque value is the original soil, the green torque value is the final improvement
(For detailed stirring process and motor current data, please refer to the import drawing curve)
Through the above test data, it can be determined how the project uses a combination of foam and bentonite to jointly improve the flow plastic effect of the slag.
Water-rich layer experiment
In particular, considering the sudden encounter with water-rich layer during the progress of the project, or the sudden underground water gushing that causes the slag of the screw machine to gushing water and sand, it is added how to use the diluent of polymer when simulating the accumulation of water in the soil bunker. Stop the water.
Selecting the correct soil improvement method for different layer can significantly improve construction efficiency. Our company is very willing to communicate with our customers and provide relevant technical parameters and experimental programs.