Drilling and cutting method of magnetic conversion type tool change for hard and soft formations

Abstract

The invention belongs to the technical field of underground engineering rock and soil body drilling and cutting, and underground engineering disaster prevention and reduction, and provides a magneticconversion type tool change drilling method for soft and hard stratums. When the in-hole tool change operation is carried out, a telescopic controller is used for controlling the retraction of a telescopic rod to drive a magnetic block and a first set of drill bit fixing plates to retract together, when the height of the other set of drill bit fixing plates is reached, the magnetization function ends, and the magnetic block is separated from the first set of drill bit fixing plates; a lifting sliding rod set is controlled to rotate by a certain angle, so that the other set of drill bit fixingplates can be coincided with the axis of the magnetic block in the vertical direction; then the magnetic block is driven to descend; the magnetic block is controlled to be magnetically connected withthe other set of ferromagnetic drill bit fixing plates, and the in-hole replacement of the cutters is completed. Meanwhile, the rapid drilling and cutting construction of the soft and hard stratums can be achieved through variable drilling and cutting, and any stratum rock debris can be quickly discharged through a pump water washing system, the stratum adaptability of the drill holes is improved,and the problem that the hole deviation in drilling in soft and hard stratums is large is solved.

Description

technical field [0001] The invention belongs to the technical field of underground engineering rock and soil drilling and cutting, and underground engineering disaster prevention and mitigation, and in particular relates to a magnetic conversion type tool-changing drilling and cutting method for soft and hard formations. Background technique [0002] Soft and hard stratum is a kind of heterogeneous stratum with complex and changeable geology. It is an engineering problem faced in the process of underground engineering construction, such as shield tunnel passing through soft and hard stratum, pile foundation construction passing through soft and hard stratum, deep foundation pit Precipitation passes through soft and hard strata, subsidence marks on the ground in the subway operation area pass through soft and hard strata, and energy-gathering slits in deep rock and soil pass through soft and hard strata, etc. When encountering soft and hard ground during the construction of u...

AI Technical Summary

Problems solved by technology

When encountering soft and hard ground during the construction of underground projects, sufficient attention must be paid, otherwise it will cause quality accidents such as pile position deviation, loose concrete segregation, cracks, mud inclusions, surface settlement, underground pipeline damage, and surface buildings tilting or collapsing. This is because the formation crossing construction is different from the construction of single soft and hard formations. Due to the large difference in rigidity between soft and hard formations, the drilling speed and the reaction force of different soft and hard formations on the drilling and cutting tools are not equal, resulting in soft and hard formations. Drillability of formations differs from single soft and hard formations, resulting in drilling and cutting forces at the working face that are more difficult to control than in single soft and hard formations

[0003] Existing drilling devices for soft and hard formation mainly include super large diameter shield cutter head, shield scraper, shield machine tool, PDC bit, geophysical scour bit, etc. The cutting device is mainly rock-socketed pile air-pressure-controlled cutting, but shield drilling devices such as super-large-diameter shield cutterhead, shield scraper, shield machine tool, etc. are bulky and expensive. Drilling devices such as engineering survey drilling devices have small hole diameters, blade distribution angles and cutter distribution settings are unreasonable, and when rock-socketed piles are controlled by air pressure to cut soft and hard strata, the cutting force of the cutting surface cannot change in real time with the stratum. needs improvement

Therefore, the existing drilling and cutting devices for the construction of soft and hard formations are mainly single drilling devices and cutting devices, lacking a composite drilling and cutting device with both drilling and cutting functions.

[0004] Chinese patent CN106907158A is a super-large-diameter shield cutterhead system for soft and hard uneven formations, including large cutterheads, medium-sized cutterheads, small cutterheads, spokes, panels, hobs, cutters, leading knives, center knives, Stirring rods, reducers, hydraulic motors, power transmission devices, shields, and screw excavation devices, but the layout of the cutterhead system is a multi-layer cutterhead space staggered distribution, which is expensive. When the cutterhead encounters soft and hard strata for drilling construction However, due to the limitation of the overall structure of the front cutter head of the shield machine, the shield machine can only be driven into soft and hard areas by controlling various cutter heads, and it is difficult to effectively control the drilling and cutting forces of the corresponding cutting surfaces in different layers of soft and hard layers. , at the same time it cannot cut hard formations in soft and hard formations

[0005] Chinese patent CN206495679U is a kind of shield scraper used in soft and hard uneven formations. There is a hard alloy on the back of the body, and a wear-resistant alloy layer on the cutting edge of the cutter body. However, the shield scraper is mainly to enhance its impact resistance in bad formations, and the cost is high, so it cannot guarantee the protection of soft and hard formations. The accuracy of the main structure during construction cannot be used for drilling and cutting rock and soil in soft and hard formations

[0006] Chinese patent CN204552753U is a shield machine tool suitable for soft and hard uneven strata, including multiple tool combinations installed on the cutter head. The tool combination includes hobs and cutting knives. The shaft of the hob is equipped with sensors. The rear part is fixedly installed on the cutter head, and the rear part of the cutter is installed on the cutter head through a base with a hydraulic expansion device. The base can move back and forth along the shield machine axis, but the shield machine tool is limited The front cutterhead of the shield machine is an integral structure, which can only be drilled into the rock and soil by controlling the hob and cutter, and cannot accurately adjust the penetration of the shield cutterhead during construction in various strata such as soft stratum, hard stratum, and soft-hard stratum. The drilling force of the surface is high, and the cost is high, and the hard formation in the soft and hard formation cannot be cut

[0007] Chinese patent CN203891774U is a five-blade PDC drill bit suitable for soft and hard formations, including a drill body and five blades protruding from the crown of the drill body, and several grooves for discharging debris are formed between the blades , the drill bit drills holes by adjusting the distribution angle of the blade and the distribution of the main cutting teeth on the blade. It cannot guarantee the stress uniformity of the main structure in soft and hard formations, and cannot be used for drilling and cutting in soft and hard formations in rock and soil.

This device is mainly aimed at the stress situation when cutting soft and hard rocks. It maintains constant pressure on the soft rocks that are drilled and applies air pressure to the hard rocks that are not fully cut. The problem of real-time adjustment of the cutting force on the cutting surface of different formations such as strata, and the rapid discharge of chips when cutting soft and hard formations cannot be solved, especially hard formations cannot be cut, and the force uniformity of the cutting device cannot be maintained

Images