Abstract: A process for producing refined cotton with a high polymerization degree includes: a. selection of material; b. impurity removal; c. impregnation; d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide in equal proportion to form a cooking compound adjuvant with a mass concentration of 0.2-0.5%, putting the cooking compound adjuvant into a spherical digester together with the cotton linter subjected to the impregnation treatment, heating to 70 C, stopping heating, and subjecting to idling pretreatment for 40-60 min; e. cooking; f. cooling of the spherical digester; g. formulating a chlorine dioxide bleaching stabilization solution; h. a first stage of bleaching; I. alkali treatment; J. a second stage of bleaching; K. dechlorination; and l. rolling and drying by baking.

Abstract: A volume measurement system and method for a closed water-filled karst cave, including a water collecting device, concentration tester and control system. The control system is connected to the water collecting device by a connecting piece. The water collecting device is a container with a top closed and bottom open. The water collecting device top is a piston. The piston is connected to a propulsion rod, and propulsion rod is controlled by control system to extend or retract, so as to realize the forward or backward movement of the piston. An openable and closeable placement table is hinged to the water collecting device's inner wall. The placement table is connected to piston, the placement table moves upward when piston is raised, and placement table moves downward when piston is lowered. The placement table is configured to accommodate a chemical substance. The concentration tester is configured to detect the solution's concentration.

Abstract: Fully automatic true triaxial tunnel and underground project model test system, including a triaxial loading device for loading model test piece, automatic data collection and analysis device, power system and control system; triaxial loading device includes test bench, vertical loading system, horizontal front and back, and left and right loading systems, and the vertical, horizontal front and back, and left and right loading systems apply three-way pressure to model test body; test bench functions for supporting, fixing, and providing counter-force; automatic data collection and analysis device includes micro optical fiber sensor embedded in model test piece, optical fiber monitoring system, micro pressure box and strain brick, and can collect multi-field information.

Abstract: A platform, system, and method for simulating critical rock collapse of surrounding rock in underground engineering includes: four vertically arranged reaction walls defining a square reaction space, and a base mounted at a lower end opening of the wall; and a row of horizontally arranged stress loading plates at a side of each wall close to the reaction space, and a reaction beam above this space, where the reaction beam, the stress loading plate, and the base define a loading space, and the loading space is configured for placement of a surrounding rock simulation block to be tested; the stress loading plate capable of moving horizontally in a direction of the reaction wall, and the reaction beam capable of moving in a vertical direction, so as to load the surrounding rock simulation block; and the stress loading plate and the reaction beam being driven by linear motion units for movement.

Abstract: A discrete element method contact model building method includes: selecting a filling body in a disaster-causing structure to obtain a change rule of cumulative loss of the filling body ; performing test simulation, and determining a relation function of each group of corresponding mesoscopic mechanical parameters in each time period and mesoscopic parameters of a DEM contact model representing a change rule of macroscopical parameters of the filling body; embedding each mesoscopic parameter relation function into an existing particle contact model, performing test simulation, and updating a fracture failure criterion of the contact model according to a corresponding relation of macro-mesoscopic strength during model failure; and based on a seepage failure indoor test, building a seepage failure discrete element calculation model, and simulating the seepage failure process of a rock and soil mass by using the obtained particle contact model and the fracture criterion of the particle contact model.

Abstract: A peridynamics method and system for tunnel rock mass failure water inrush catastrophe simulation. A calculation model is discretized into material points, and a virtual boundary layers is set on an outer side of a boundary of the calculation model as an object to which boundary conditions are applied; a size of a horizon of the material points is selected to form a neighborhood matrix; a crustal stress is made equivalent to a stress boundary condition of the calculation model, a karst cave water pressure is made equivalent to a normal pressure, and a displacement constraint and tunnel support are converted into a displacement boundary condition; a speed and a displacement of the material point are solved, and local damage situations are recorded; and a tunnel construction process is simulated by material point dormancy after initial balance calculation is stable.

Abstract: A rock mass engineering cross-scale simulation calculation method based on REV all-region coverage, including establishing a rock mass engineering scale calculation model of particles and joints, and providing the model with particle material parameters and contact parameters; performing model region division dividing the model into multiple finite elements, and performing all-region coverage and mesh division using the finite elements, wherein a volume of the finite element is equal to a representative elementary volume of a REV model; and applying boundary conditions, calculating force and motion information of finite element nodes using a continuous medium method, obtaining a failed finite element according to the node force and motion information, and calculating motion information of particles of the REV model in the failed finite element using a discontinuous medium method. According to the calculation method, the calculation efficiency is improved, and the accuracy of calculation results is ensured.

Abstract: A system and method for rock mass structure detection and dangerous rock detection including a rock mass structure automated detection device and a server. The rock mass structure automated detection device includes a three-dimensional laser scanning device and a two-dimensional image acquisition device for respectively acquiring three-dimensional laser point cloud data and a two-dimensional image of a tunnel construction region. The server communicates with the rock mass structure automated detection device and includes a block structure three-dimensional modeling module and a block structure geometric stability analysis module.

Abstract: A volume measurement system and method for a closed water-filled karst cave, including a water collecting device, concentration tester and control system. The control system is connected to the water collecting device by a connecting piece. The water collecting device is a container with a top closed and bottom open. The water collecting device top is a piston. The piston is connected to a propulsion rod, and propulsion rod is controlled by control system to extend or retract, so as to realize the forward or backward movement of the piston. An openable and closeable placement table is hinged to the water collecting device's inner wall. The placement table is connected to piston, the placement table moves upward when piston is raised, and placement table moves downward when piston is lowered. The placement table is configured to accommodate a chemical substance.

Abstract: A test device and a test method of fractured rock mass collapse and blockfall and fracture water inrush includes a fractured rock mass preparation device, a water source loading device, a surrounding rock pressurization device and a slide rail, wherein the fractured rock mass preparation device is fixed at one end of the slide rail, and the water source loading device is fixed on the other side of the slide rail. An opening is formed in the rock mass water storage structure, and the size of the opening is adapted to the size of the fractured rock mass; the surrounding rock pressurization device includes one bracket and a pressurization structure arranged below the bracket, and a space for accommodating the fractured rock mass is reserved below the pressurization structure; and the bottom support and the bracket are both movably installed on the slide rail.

Abstract: Fully automatic true triaxial tunnel and underground project model test system, including a triaxial loading device for loading model test piece, automatic data collection and analysis device, power system and control system; triaxial loading device includes test bench, vertical loading system, horizontal front and back, and left and right loading systems, and the vertical, horizontal front and back, and left and right loading systems apply three-way pressure to model test body; test bench functions for supporting, fixing, and providing counter-force; automatic data collection and analysis device includes micro optical fiber sensor embedded in model test piece, optical fiber monitoring system, micro pressure box and strain brick, and can collect multi-field information.

Abstract: A test device and a test method of fractured rock mass collapse and blockfall and fracture water inrush includes a fractured rock mass preparation device, a water source loading device, a surrounding rock pressurization device and a slide rail, wherein the fractured rock mass preparation device is fixed at one end of the slide rail, and the water source loading device is fixed on the other side of the slide rail. An opening is formed in the rock mass water storage structure, and the size of the opening is adapted to the size of the fractured rock mass; the surrounding rock pressurization device includes one bracket and a pressurization structure arranged below the bracket, and a space for accommodating the fractured rock mass is reserved below the pressurization structure; and the bottom support and the bracket are both movably installed on the slide rail.

Abstract: Device and method for measuring true triaxial creep of a geotechnical engineering test block, including a supporting structure; the device includes four confining pressure-plates and upper-and-lower compression-plates forming an enclosed cavity for the test block; confining pressure-plates include two long confining pressure-plates and two short-confining pressure-plates, upper-and-lower compression-plates are rectangular top and bottom steel-plates, two L-shaped long confining pressure-plates bent towards the outer side lapped on two adjacent side faces of the bottom steel-plate, two L-shaped short-confining pressure-plates bent towards the outer side lapped on remaining two-side faces of the bottom steel-plate, and bottom ends of the short-confining pressure-plates are placed on the bottom steel-plate; top ends of long confining pressure-plates lapped on the top steel-plate, and top steel-plate leans against inner side faces of two short-confining pressure-plates; vertically pressure sensors corresponds to

Abstract: Device and method for measuring true triaxial creep of a geotechnical engineering test block, including a supporting structure; the device includes four confining pressure-plates and upper-and-lower compression-plates forming an enclosed cavity for the test block; confining pressure-plates include two long confining pressure-plates and two short-confining pressure-plates, upper-and-lower compression-plates are rectangular top and bottom steel-plates, two L-shaped long confining pressure-plates bent towards the outer side lapped on two adjacent side faces of the bottom steel-plate, two L-shaped short-confining pressure-plates bent towards the outer side lapped on remaining two-side faces of the bottom steel-plate, and bottom ends of the short-confining pressure-plates are placed on the bottom steel-plate; top ends of long confining pressure-plates lapped on the top steel-plate, and top steel-plate leans against inner side faces of two short-confining pressure-plates; vertically pressure sensors corresponds to