Abstract: Provided is a method for reconstructing a water-retaining and water-blocking layer by grouting in a mining area, including: performing geophysical exploration within a space from an aquifer to a goaf in a coal mining remediation zone of a mining area to obtain a first apparent resistivity at each of positions within the space, and selecting positions within the space where the first apparent resistivity is less than or equal to a first preset resistivity to form a first dominant water-conducting channel zone; performing a water flow direction test in at least two monitoring wells within the coalmining remediation zone to obtain a first flow direction fitting function for each monitoring well, and selecting two first flow direction fitting functions to calculate a first flow direction intersection; and determining that the first dominant water-conducting channel zone is accurate and performing a grouting operation on the first dominant water-conducting channel zone.

Abstract: A jacking force prediction method for a whole construction process by a vertical jacking method, based on a spherical hole expansion theory and a shear failure principle, uses two jacking force calculation models. The models include a spherical hole expansion-sliding friction model and a shear failure-sliding friction model, and corresponding calculation formulas are deduced. When an overlying soil layer is high and the jacking force calculated by adopting the spherical hole expansion-sliding friction model is relatively small, a spherical hole expansion problem occurs at a vertical pipe cover. When the overlying soil layer is relatively low and the jacking force calculated by adopting the shear failure-sliding friction model is relatively small, a soil body failure form at the vertical pipe cover is shear failure.

Abstract: Disclosed is a method of segmented grouting for repairing aquifers in a mining area after mining. The method may include: drilling a grouting hole in a ground area corresponding to a water inflow position in a goaf; and performing a segmented grouting in a target grouting layer through the grouting hole. The segmented grouting may include: a scour and migration grouting, a splitting and diffusion grouting, and a sedimentation and compaction grouting. The scour and migration grouting may use a first slurry with a first specific gravity and a first pump volume for grouting. The splitting and diffusion grouting may use a second slurry with a second specific gravity and a second pump volume for grouting. Moreover, the sedimentation and compaction grouting may use a third slurry with a third specific gravity and a third pump volume for grouting.

Abstract: Disclosed is a grouting and water blocking method for a hard rock stratum. The grouting and water blocking method include the following steps. At first, hydrogeological information and coal seam information of a hard rock stratum is obtained. Then, a drilling trajectory of the hard rock stratum is determined based on the hydrogeological information and the coal seam information. Later, at least one drilling device is determined corresponding to the drilling trajectory based on types of multiple rock layers contained in the hard rock stratum. After that, the multiple rock layers contained in the hard rock stratum are drilled sequentially according to the drilling trajectory using the at least one drilling device. At last, in response to determining there is a water leakage area, the water leakage area is grouted.

Abstract: A directional drilling method applied to a rigid bending joint directional drilling device includes: obtaining geological data; determining a lateral drilling point and a target point of a branching borehole based on the geological data; drawing a target borehole trajectory of the branching borehole based on the lateral drilling point and the target point; obtaining parameters of the drill pipe; determining a propulsion force corresponding to the target borehole trajectory based on the parameters, the target borehole trajectory, and the geological data; and applying the propulsion force to the rigid bending joint directional drilling device for drilling the branching borehole. A directional drilling system and related devices are also disclosed.

Abstract: Disclosed is a method for repairing an aquifer in a coal mine area by grouting, including: drilling a survey hole in a ground area corresponding to a water inflow position from ground surface to a caving zone in a goaf; determining a target layer for grouting in the survey hole based on drilling data collected from the survey hole while drilling; changing the survey hole to a grouting hole; measuring a first water level from the grouting hole; grouting through the grouting hole; changing the grouting hole to an observation hole; measuring a second water level from the observation hole; and determining a water retention level based on the first water level and the second water level.

Abstract: A telescopic device includes a first U-shaped connector with a plurality sets of adjustment slots defined in two sides thereof and arranged along an adjustment direction; a second U-shaped connector defining first through holes in two sides thereof, the second U-shaped connector being inserted into the first U-shaped connector with U-shaped openings thereof opposite to each other to define an accommodating space; a first spring located in the accommodating space and abutting against the first and second U-shaped connectors, respectively; an elastic pin with two ends thereof extending through the first through holes and engaging into one of the plurality sets of adjustment slots; and an initial fixing pin being detachably connected to the first and second U-shaped connectors. A telescopic annular tunnel steel arch includes an upper arch, two lower arches and two telescopic devices connecting two ends of the upper arch to the two lower arches, respectively.

Abstract: A curvature controllable directional drilling device is disclosed. The drilling device includes: a drill bit, a power unit, a rigid bending unit, a bendable outer wall, and a wedge deflection tool. The power unit is to provide a rotary power to the drill bit. The rigid bending unit is set between the drill bit and the power unit, to bend on a basis of an initial curvature under an external force. The bendable outer wall is set on an outer side of the power unit and the rigid bending unit. The wedge deflection tool is set at one end of the bendable outer wall near the drill bit, to receive a reaction force and bend the rigid bending unit. By a coordination between the wedge deflection tool and the power unit, a drilling direction of the drill bit connected to the rigid bending unit can be adjusted.

Abstract: A telescopic device includes a first U-shaped connector with a plurality sets of adjustment slots defined in two sides thereof and arranged along an adjustment direction; a second U-shaped connector defining first through holes in two sides thereof, the second U-shaped connector being inserted into the first U-shaped connector with U-shaped openings thereof opposite to each other to define an accommodating space; a first spring located in the accommodating space and abutting against the first and second U-shaped connectors, respectively; an elastic pin with two ends thereof extending through the first through holes and engaging into one of the plurality sets of adjustment slots; and an initial fixing pin being detachably connected to the first and second U-shaped connectors. A telescopic annular tunnel steel arch includes an upper arch, two lower arches and two telescopic devices connecting two ends of the upper arch to the two lower arches, respectively.