Sigma Plantfinder recently Shipped another Jet-grouting unit to Thailand.
The Jet-grouting unit that has recently set off on its journey to Bangkok, Thailand is a Tecniwell TW352 Compact Jet-grouting unit.With its High Pressure Triplex Pump and a Powerful 425Hp engine it is capable of maximum pressure of up to 800 bar and an impressive flow rate of up to 480 litres a minuet!
If you are in the market for a Jet Grouting Rig or a Jet Grouting High Pressure Pump that offers superior performance and durability, them Sigma Plantfinder Ltd. could have what you’re looking for.
So What Is Jet Grouting?
Jet Grouting can come under various different names and headings like Soilcrete, Jetcrete, Soil Cement Columns to name but a few with the resulting Ground improvement foundation being Mixed In-Situ or Mixed in place (MIP) and refers to mixing the existing soil in situ with a binding agent.
Unlike some usual forms of grouting that permeate through the soil, Jet grouting is a method of ground reinforcement that uses high kinetic energy in the form of a high velocity jet of grout to breakdown the soil structure and simultaneously mix cement grout with the in-situ soil.
Why Is Jet Grouting Used?
Jet Grouting increases soil strength and reduces ground deformation, reduces soil permeability and treats the ground, when other methods of grouting are unsuitable.
Jet grouting can be effective in all types of soil, this is the distinct advantage of Jetcrete or Soilcrete High Pressure Grouting over against the classical grouting techniques, which rely on permeation through voids in the surrounding soil.
Jet Grouting can be used in tunnelling, underpinning, ground retaining systems, cut-off barriers, base plugs of shafts, and to create high modulus/controlled stiffness grout columns giving highly compressible soils to reduce settlement and increase bearing capacity.
How Does Jet Grouting Work?
The basic equipment for Jet Grouting consists of a stationary grout production plant (silos, grout mixer, high pressure pump), coupled to a drilling rig with high pressure grout lines.
The basic equipment consists of a stationary grout production plant (silos, grout mixer, high pressure pump) that is connected to a drilling rig with high pressure grout lines. The drilling bit is equipped also with injection nozzles, the types of which will depend on the type of soil and on the shape, size and strength of the column or element required to be formed.
At each injection point the following procedure will be carried out:
- The rig is positioned at the drilling location.
- A small diameter hole around 70 to 120 mm in size is drilled through the layer of soil requiring treatment.
- Grout is pumped through the drilling rod with a very high flow of between 200 to 400 L/min from the high¬ pressure pump and is sprayed through one or more of the small diameter injection nozzles on a monitor at the tip of the drilling rod.
- Slowly the drilling tool is withdrawn, whilst either fully rotating the drilling rod for column formation or partially rotating if panel formation is required.
Methods of Jet Grouting
There are three jet grouting methods. Selection of the most appropriate method is generally determined by the soil conditions, the in situ soil, the application, and the physical characteristics of soil-cement mix (i.e. strength) required, the geometry of the element to be constructed and the application.
- Single Fluid Jet Grouting
The single fluid system is the simplest. Grout is pumped through the rod and exits the horizontal nozzle or nozzles in the monitor at high velocity. This jet breaks down the soil matrix and replaces it with a mixture of grout slurry and in situ soil. Single fluid jet grouting is most effective in cohesionless soils. The single fluid system is capable to form a column up to 180cm in diameter.
- Double Fluid Jet Grouting
The double fluid system is the simultaneously injection of high velocity grout stream within a cone of compressed air. The double fluid system is able to create a larger column than the single fluid system. The double fluid system is more effective in cohesive soils than the single fluid system and is able to form a column up to 180cm in diameter.
- Triple Fluid Jet Grouting
The triple fluid system is the most complicated jet grouting system due to the simultaneous injection of three different fluids, air, water, and grout. Grout emerges at a lower velocity from separate nozzle or nozzles below the erosion Air and Water jets. This separates the erosion process from the grouting process and tends to yield a higher quality soil-cement mix and a larger radius is achieved of up to 300cm in diameter.
The characteristics of the jet grouting elements, which are the columns diameters, length of the panels, permeability, composition of the mix, compression strength etc., depend on the treatment parameters or extraction speed, rotation speed, grout injection pressure, flow and density etc, the soil conditions or type of soil and grain size distribution, compaction etc., and on construction method whether it be single, double or triple fluid jet grouting.
Types of grouting that can be carried out range from single curtain walls, double curtain walls, Plugs, Secant columns walls, reinforcing columns and cross section columns.
Jet Grouting applications are wide and varied, some of which are listed below:
Excavation support, temporary and permanent shoring and shoring for access shafts
Projects with limited headroom or in cramped spaces, underpinning of existing structures; and tunnel liners or stabilization.
various foundation structures like footings and slabs, Ground improvement under uniform loading like heavy storage platforms, embankments, quays and slabs or under localised loads like building footings and bridge piers. A load transfer platform (LTP) is usually required above the jet grouting columns.
Underpinning or settlement mitigation, excavation of additional underground floors below existing building, excavation along existing structures
single pile with or without steel reinforcement, casings or bars.
Impervious cut-off walls and bottom plugs for deep excavations can be formed by jet grouting and is particularly suitable for deep shaft construction below ground water level or near sensitive structure
Retaining walls using secant Jet-grout columns designed as gravity walls or cantilever walls. Steel reinforcement, lube, rebars or cages can be inserted in the Jet Grouting columns as required
Reinforcement of soils where existing utility lines and buried structures are present.
Sigma Plantfinder Ltd have available for sale a vast assortment of Used Jet Grouting Drilling Rigs and Jet Grouting pumps and Equipment for sale,
Get in touch to find out more about this equipment and discuss your needs.