The present disclosure relates to a grouting material for reinforcement of coal-rock mass in low-temperature mining. The material includes a component A and a component B, where the component A includes 100 parts of a polyether polyol A and 0.05 parts to 0.1 parts of a catalyst; the component B includes 18 parts to 24 parts of a polyether polyol B, 21 parts to 26 parts of a flame retardant, 50 parts to 61 parts of polyisocyanate, and 0.05 parts of the catalyst. A preparation method of the grouting material includes the following steps: stirring the polyether polyol A and the catalyst to obtain the component A; drying the polyether polyol B and mixing with the polyisocyanate and the catalyst, and conducting a reaction to obtain an isocyanate prepolymer; adding the flame retardant to the isocyanate prepolymer, and adjusting a viscosity to obtain the component B.

The present disclosure relates to a grouting material for reinforcement of coal-rock mass in low-temperature mining. The material includes a component A and a component B, where the component A includes 100 parts of a polyether polyol A and 0.05 parts to 0.1 parts of a catalyst; the component B includes 18 parts to 24 parts of a polyether polyol B, 21 parts to 26 parts of a flame retardant, 50 parts to 61 parts of polyisocyanate, and 0.05 parts of the catalyst. A preparation method of the grouting material includes the following steps: stirring the polyether polyol A and the catalyst to obtain the component A; drying the polyether polyol B and mixing with the polyisocyanate and the catalyst, and conducting a reaction to obtain an isocyanate prepolymer; adding the flame retardant to the isocyanate prepolymer, and adjusting a viscosity to obtain the component B.

The purpose of the present invention is to provide a determining device and a determining method to determine whether an inspected jet nozzle is defective by inspecting the jet nozzle for injecting a jet stream with long ground penetrating distance at a stage before installing in a construction site where a large diameter jet grouting method is used. To achieve this purpose, with this invention, in which a nozzle to be inspected is mounted onto an outlet port, a jet stream is ejected from a jet stream generating device, and measurement data measured by a pressure sensing unit when the jet stream impacts the pressure sensing unit is processed with a controlling device (for example, a computer), a nozzle to be inspected is determined to be a non-defective product if a first ratio is no less than a first prescribed value, a second ratio is no less than a second prescribed value, and a third ratio is no less than a third prescribed value.

The disclosure relates to a device for reinforcing a ground on which is disposed a loading structure. Threaded inclusions are disposed vertically within the ground and reinforce said ground. The core diameter of threaded inclusions is between 250 mm and 450 mm and the external diameter is between 350 mm and 600 mm. A load transmitting layer is interposed between the ground and the loading structure disposed thereon, so as to transmit and distribute the load from the loading structure to both the ground and the plurality of inclusions. A ratio between a distance between axes of two adjacent inclusions and the internal diameter of said adjacent inclusions is between 4 and 14, and the inclusions are made from a material having a specified 28-day compressive strength between 5 MPa and 35 MPa.

The disclosure relates to a device for reinforcing a ground on which is disposed a loading structure. Threaded inclusions are disposed vertically within the ground and reinforce said ground. The core diameter of threaded inclusions is between 250 mm and 450 mm and the external diameter is between 350 mm and 600 mm. A load transmitting layer is interposed between the ground and the loading structure disposed thereon, so as to transmit and distribute the load from the loading structure to both the ground and the plurality of inclusions. A ratio between a distance between axes of two adjacent inclusions and the internal diameter of said adjacent inclusions is between 4 and 14, and the inclusions are made from a material having a specified 28-day compressive strength between 5 MPa and 35 MPa.

Described herein are tools, systems and methods for conditioning, strengthening and/or improving in situ soil geotechnical or agricultural properties while at least temporarily reducing soil density, energy requirements, and tool wear.

The invention relates to a ground-working machine and a method for producing wall panels, with the ground-working machine having at least two elongate drilling and mixing tools arranged parallel to each other, which comprise a rod-form base body, on which a first screw conveyor and at least one second screw conveyor are arranged, the second screw conveyor being axially spaced apart from the first screw conveyor. According to the invention it is provided that at least on one drilling and mixing tool at a lower end the first screw conveyor is formed with an outer diameter that is greater than an outer diameter of the second screw conveyor which is arranged above the first screw conveyor.

A spray assembly for a working machine that includes a fluid storage tank includes a plurality of nozzle assemblies, each of which includes a direct acting valve. The spray assembly also includes a controller that is operatively connected to each of the direct acting valves for controlling the opening and closing of the direct acting valves, and a selector that is operatively connected to the controller. The selector may be employed by an operator of the working machine to selectively operate one or more of the direct acting valves in order to provide a desired spray pattern of fluid from the fluid storage tank.

The porous displacement piles comprising (a) closed-ended pipe piles with small holes and or narrow slots, filled with compacted sandy soil, (b) closed-ended porous pipe piles such as closed-ended pipe pile with very small holes and or very narrow slots, and (c) a precast prestressed porous concrete piles are driven through inside the already driven non-displacement hollow pipe piles in a grid pattern to create excess pore-water pressures generally ranging between 50 and 1500 kPa in cohesive soils, which begin dissipating through inside the porous displacement piles to rapidly consolidate and densify the said cohesive soil. The porous displacement piles are designed for permitting free flow of the pressurized pore-water and to prevent migration of particles of cohesive soil into the porous displacement pile using filter design criteria or verified by laboratory tests. These piles when driven in sandy soils densify sandy soils instantaneously.

A process for treating a tailings stream comprising water, solids, and optionally polyacrylamide. The process involves (a) contacting the tailings stream with a silicate source for a pre-determined period of time to form a mixture; b) after a pre-determined period of time of at least 5 minutes, contacting the mixture with an activator to initiate gel formation, wherein the gel entraps the solids within the gel; and c) allowing the gel to strengthen and solidify; wherein the gel formation is delayed compared with a non-delayed process.