595 results about "Shotcrete" patented technology

The invention relates to the technical field of concrete materials, and discloses rapidly-reinforced high-performance sprayed concrete for an existing tunnel lining and a preparation method of the rapidly-reinforced high-performance sprayed concrete. The sprayed concrete is prepared from the following raw materials in parts by weight: 300 to 350 parts of low-calcium high belite sulphoaluminate cement, 80 to 100 parts of superfine slag powder, 3 to 8 parts of a trigger type activating agent, 5 to 15 parts of slow-release particles, 2 to 5 parts of nanogel, 800 to 900 parts of fine aggregate, 800 to 900 parts of coarse aggregate, 30 to 50 parts of copper-plated steel fiber, 0.8 to 1.2 parts of polypropylene fiber, 30 to 40 parts of a viscosity-adjusting accelerator, 10 to 20 parts of a water reducing agent and 160 to 180 parts of water. The sprayed concrete is high in compressive strength and good in durability, the double threats of chemical corrosion and chloride ion permeation / steel bar corrosion are cooperatively solved, and the requirement for rapid reinforcement of tunnels and underground engineering is met.

The invention discloses solid waste-based fiber reinforced sprayed concrete and a preparation method thereof, and belongs to the technical field of concrete. The sprayed concrete is prepared from the solid waste-based cementing material, the fine aggregate, the basalt fiber, the water reducing agent, the accelerator and the water, the slag, the carbide slag, the fly ash and the cement serve as the solid waste-based cementing material, part of the cement is replaced by the fly ash and the slag, the slag can make up for the deficiency of the activity of the fly ash in the early stage, the early strength is rapidly improved, and the early strength is improved. The rebound rate is reduced; the fly ash further densifies the matrix in the later period by means of continuous pozzolanic reaction, so that the durability is enhanced; the basalt fibers, the accelerator and the water reducing agent are mixed, the hydration process is optimized, and the synergistic enhancement effect of the fibers and a matrix is achieved, so that the generation of early cracks and the development of later cracks are inhibited, and finally the sprayed concrete with high strength, high toughness and low shrinkage is obtained.

The invention discloses a primary support early-age sprayed concrete safety assessment method under cyclic blasting load, and relates to the field of concrete reliability analysis, and the method comprises the following steps: determining geometric parameters of a to-be-protected tunnel, and establishing a tunnel finite element model; determining a blasting load by using a detonation wave theory, and applying the load to the model for finite element analysis to obtain residual deformation data of each extraction point; determining a blasting load influence range; monitoring the environment temperature time sequence data of the evaluation sub-section, and representing the hydration degree and the water content of the evaluation sub-section; according to the method, the mapping relation between the mechanical characteristic parameters and the hydration degree and the water content is established, the mechanical characteristic parameters of the concrete are calculated, the safety of the sprayed concrete is determined by comparing damage with a safety difference standard, and the scientificity of safety evaluation of the sprayed concrete is improved.

The invention discloses an alkali-free accelerator and a preparation method and application thereof in the technical field of concrete additives, and the alkali-free accelerator provided by the invention comprises the following components in percentage by mass: 40%-50% of aluminum sulfate, 10%-15% of magnesium sulfate, 0.2%-0.6% of diethanol amine, 0.5%-1% of catechol-4-ammonium sulfonate, 5%-10% of a stabilizer and the balance of water. The stabilizer comprises silicate dispersion liquid and silica sol. The alkali-free accelerator provided by the invention can be used for spraying concrete, the mixing amount of the alkali-free accelerator is generally 4-6% of the mass of cement, the alkali-free accelerator is good in rapid setting effect and has excellent early and later compressive strength, and meanwhile, the alkali-free accelerator has relatively excellent stability.

The invention discloses a soft rock waterproof layer construction method for a soft rock large-deformation section tunnel, and relates to the technical field of soft rock waterproof layer construction of the soft rock large-deformation section tunnel. The construction method of the soft rock waterproof layer for the tunnel at the large deformation section of the soft rock comprises the steps that a sprayed concrete layer is constructed, a full-ring-shaped steel arch frame is erected, system anchor rods are constructed, concrete is sprayed again after full-length grouting is conducted, and a primary supporting layer containing a grouting reinforcing ring is formed; locking anchor pipe grouting is carried out on the arch springing part to form a local reinforced waterproof bearing body; based on deformation monitoring data, dynamic judgment is carried out, and radial reinforcing grouting is carried out on the obvious deformation part; and after deformation is stable, a waterproof layer is laid, a secondary lining is poured, and a composite waterproof system is formed. The waterproof reliability and the structural durability of the soft rock waterproof layer of the tunnel at the large deformation section of the soft rock can be improved.

The invention relates to the technical field of preparation of new materials for coal mine tunnel construction, in particular to a mining ultrahigh-strength sprayed concrete active admixture and a preparation method of the mining ultrahigh-strength sprayed concrete active admixture. The prepared UHPC has excellent jet constructability, rapid hardening performance and long-term durability, realizes nearby high-valued utilization of coal mine solid waste, solves the problems of low strength, high rebound rate and long maintenance period of a traditional roadway spraying material, can replace traditional guniting concrete to be used for rapid support construction and repair of a coal mine roadway, and has a wide application prospect. And the method has remarkable technical economic benefits and social benefits.

This invention discloses a heat-insulating and heat-resistant shotcrete and its preparation method. This heat-insulating and heat-resistant shotcrete is composed of cement, modified silica mortar, modified heat-insulating ceramsite, fine aggregate, water, admixtures, and accelerators. In this invention, high-strength shale ceramsite with surface modification using hydrogel is introduced as a heat-insulating filler, significantly improving the dispersion and stability of lightweight aggregate in the mortar. It also possesses strong water absorption and slow-release capabilities and surface sealing functions, enabling it to provide pore insulation and internal curing through water storage and release in high-temperature environments. The addition of modified silica mortar, which effectively improves the high-temperature stability and density of the mortar hydration products, comprehensively enhances the homogeneity of the shotcrete mixture, the heat insulation performance of the hardened body, and the strength development and durability under high-temperature conditions. This effectively improves tunnel chamber temperature and extends the service life of the shotcrete under high-temperature conditions. The heat-insulating and heat-resistant shotcrete technology has a clear working mechanism, simple production process, and excellent performance. It is suitable for large-scale production and is of great significance for the high-quality construction of underground projects such as tunnels and mines in high-temperature and high-temperature water inrush environments.

The invention discloses a full-space active and passive reinforced supporting method for a deep roadway, and relates to the technical field of deep roadway supporting. The method comprises the following steps: S1, obtaining a roadway surrounding rock structure, ground stress and surrounding rock physical and mechanical parameters; s2, determining the ranges of a broken area, a plastic area and an elastic area of the surrounding rock of the deep roadway; s3, variable-diameter pressure relief drill holes are constructed to reduce the surrounding rock stress; s4, an anchor net is supported, and concrete is sprayed to block the surface of the surrounding rock; s5, grouting reinforcement is conducted, and anchor rod cables are installed; s6, a full-space concrete filled steel tube support is erected; and S7, a roadway bottom plate is poured, and concrete spraying is conducted on the surface of the surrounding rock so that the support can be embedded. According to the surrounding rock control method, active bearing of the roadway surrounding rock and passive supporting of the full-space support can be effectively coordinated, the cooperative bearing capacity of the deep roadway can be improved, and safety and stability of the deep roadway are guaranteed.

The invention provides an anchor-plate-injection collaborative supporting method for active water sealing. The anchor-plate-injection collaborative supporting method is applied to various laneways penetrating through water-containing stratums, especially to construction of vertical shafts constructed through a freezing method. During freezing method construction, a freezing wall is formed firstly, a section height is excavated, an anchor rod is drilled and constructed after the section height is excavated, and if water exists after excavation, forced drainage needs to be carried out to enable the displacement to be larger than the water inflow so as to ensure that no accumulated water exists on a working face; the steel plates are fixed through anchor rods, so that grouting gaps are formed between the steel plates and the well wall; a gap between the bottom edge of the steel plate and the well side is blocked by a certain height through foam; grout is injected through a grouting pipe on the lower portion of the steel plate, and a primary supporting structure is formed after solidification; secondary and more supporting can be carried out immediately or after primary supporting of multiple section heights is formed, and a permanent supporting structure is formed. A traditional passive waterproof mode is broken through, and active water plugging can be achieved; the method adapts to various construction methods and stratums; the temporary support is essentially different from a traditional anchor-shotcrete net temporary support, and the construction efficiency is higher.

The invention relates to the technical field of hydraulic concrete materials, and particularly discloses nano-modified anti-rebound full-hole slag sprayed concrete, which is prepared from the following raw materials in parts by weight: 665 parts of hole slag aggregate, 950 parts of hole slag sand, 396 to 436.5 parts of ordinary Portland cement, 225 parts of water, 10 parts of polycarboxylic acid type water reducing agent and 8.5 parts of accelerator, the hole slag aggregate is further modified by a nano admixture, and the nano admixture is composed of nano kaolin, nano silicon dioxide and a precise PCE solution. The springback-resistant shotcrete is prepared from the nano admixture modified hole slag aggregate, full-quantitative resource utilization of tunnel excavation hole slag is achieved, the problems of occupied area of piled slag and potential ecological pollution are effectively relieved, the cement consumption in the concrete is reduced, the construction cost is reduced, meanwhile, the springback rate of the shotcrete can be remarkably reduced, and the construction period is shortened. The compactness of the concrete is improved, and the compression resistance degree and the crack resistance of the concrete are enhanced.

The invention discloses a high / ultra-high performance concrete full-automatic injection pump truck and a construction method, the high / ultra-high performance concrete full-automatic injection pump truck comprises a walking system, an efficient pumping and precise injection system, a hydraulic and intelligent central control system, a pre-injection pre-scanning system, a spraying-while-detecting system and a post-injection quality evaluation system, and the walking system is used for achieving movement and in-place of a pump truck; the efficient pumping and accurate spraying system is used for conveying and spraying concrete; the hydraulic and intelligent central control system is used for controlling the operation of the whole pump truck; the pre-spraying pre-scanning system is used for acquiring the three-dimensional form and defect information of a construction surface before construction; the spraying-while-detecting system is used for monitoring the concrete flow state and construction parameters in the spraying process in real time; the post-spraying quality evaluation system is used for carrying out nondestructive testing on the quality of a spraying layer after construction; according to the invention, full-process intelligent closed-loop control from construction surface scanning, path planning, real-time spraying adjustment to final quality evaluation is realized, and high quality, high efficiency and intelligence of concrete spraying construction are realized.

The invention discloses a quick-hardening early-strength concrete mineral additive and a preparation method thereof, and belongs to the technical field of building materials. The additive comprises the following components in parts by weight: 50-75 parts of a mineral active material (compounded by silica fume, slag powder and metakaolin), 15-30 parts of a composite activator (sodium silicate, lithium sulfate and triethanolamine synergistically), 5-10 parts of a sustained-release microcapsule (calcium sulphoaluminate coated with nano-silica) and 2-5 parts of an auxiliary thickening agent (compounded by HPMC and a water reducing agent). The preparation method comprises the steps of mineral activation, excitant reaction and mixing of the microcapsule and the thickening agent. After the additive is doped into concrete, the 3h compressive strength is greater than or equal to 15MPa, the initial setting time is less than or equal to 5min, and the additive has low resilience (less than or equal to 13%), high durability (impermeability is greater than or equal to P11) and environmental adaptability (-5 DEG C strength fluctuation ratio is less than or equal to 9%). And compared with the prior art, the cost is reduced by 40%, and the method has remarkable economic and social benefits.

The invention discloses a variable-temperature curing method for curing a high-ground-temperature tunnel sprayed concrete test piece, and relates to the technical field of concrete construction. Comprising the following steps: acquiring concrete test piece samples with different water-binder ratios, aggregate types and additive contents, recording hydration heat data of the concrete test piece samples, and performing normalization processing to generate a training sample data set; and establishing a neural network prediction model based on the data set, inputting concrete characteristics, and outputting a hydration heat prediction value. Thirdly, calculating a hydration heat influence index in combination with the thickness and the surface roughness, and meanwhile obtaining environmental parameters in the tunnel, including temperature, humidity and wind speed to calculate an environmental influence index; and finally, dynamically correcting the curing temperature of the to-be-detected concrete test piece by utilizing the heat conductivity of the tunnel surface structure and the comprehensive environment and hydration heat influence index, so that the accuracy and effectiveness of temperature control are ensured, and the overall efficiency and quality of construction are remarkably improved.

The utility model belongs to the technical field of tunnel engineering construction, and discloses an assembly type corrugated steel plate preliminary bracing structure for a vertical shaft, which comprises an assembly type corrugated steel plate layer and a plurality of anchor rods, the assembly type corrugated steel plate layer is formed by splicing a plurality of corrugated steel plate units, and one end of each anchor rod is fixed on surrounding rock. The other end of the anchor rod is fixedly connected with the corrugated steel plate unit, and a grouting layer is filled between the assembly type corrugated steel plate layer and the surrounding rock, so that the complex links of material field processing, layered concrete spraying and the like are reduced, and the construction process is greatly simplified; in terms of construction pollution, a large amount of dust generated by sprayed concrete is avoided, the construction environment is improved, the corrugated steel plate layer cooperates with the anchor rod, the grouting layer, the reinforcing mesh and the like to form a stable supporting system, the arc-shaped corrugated steel plate body is attached to the surrounding rock, the zinc coating enhances corrosion resistance, and the foam pad improves the durability of the structure. The tunnel supporting target which is efficient, environmentally friendly, economical, stable and reliable is achieved on the whole.

The invention provides a repairable lining structure for a tunnel to pass through an active fault and a construction method of the repairable lining structure, belongs to the technical field of tunnel lining structures, and solves the problem that a lining structure for the tunnel to pass through the active fault is difficult to repair in waterproof and drainage. The primary supporting layer comprises sprayed concrete and anchor rods, the buffering energy dissipation layer comprises an outer side energy dissipation filling layer and an inner side elastic buffering layer (having the waterproof plate function), the repairable secondary lining layer is of a sectional structure, and a repairing channel is formed between every two adjacent lining sections. The lining structure provided by the invention has strong anti-dislocation performance and convenient repairability, the waterproof and drainage system and the like can be quickly repaired without dismantling an original main body structure after fault dislocation, meanwhile, the long-term operation safety of the structure is guaranteed, and the lining structure has important significance for improving the durability of tunnel engineering and reducing the maintenance difficulty of the tunnel engineering.

The invention discloses a sprayed concrete construction method for 3D printing of a building structure, and relates to the technical field of building engineering, and the method comprises the following steps: S100, based on the operation cycle of a nozzle driving system, collecting pressure waveform data in a concrete spraying process, extracting a dominant frequency and amplitude change sequence, and generating a pressure disturbance feature vector with a time label; and S200, according to the pressure disturbance feature vector, the lowest-order inherent frequency and the response sensitive bandwidth of a current printing unit are dynamically modeled in combination with the printing track layer height, the concrete age data and the forming geometric parameters, and a structure dynamic response baseline is constructed. According to the method, identification and control of injection disturbance and structure inherent frequency resonance risks are achieved, a feedforward regulation and control mechanism and a closed loop feedback mechanism are fused, the instability problem caused by structure resonance is avoided, the injection parameter adjustment precision and the path execution stability are improved, and the forming precision, the structure safety and the construction continuity in the three-dimensional printing process are guaranteed.

The invention belongs to the technical field of tunnel construction, and particularly relates to a tunnel local sprayed concrete flatness real-time detection method, which comprises an industrial computer, a wireless communication module, a mobile bearing platform, and a data acquisition unit, a transposition mechanism, a telescopic mechanism and a rotating mechanism which are arranged on the mobile bearing platform, the data acquisition unit comprises a laser distance measuring sensor used for scanning the initial spraying surface of the tunnel. According to the tunnel local sprayed concrete flatness real-time detection method, real-time and non-contact three-dimensional scanning and accurate reconstruction of the surface morphology of tunnel initial sprayed concrete are realized through arrangement of a high-precision laser distance measuring sensor and a wireless communication module and data analysis, so that the quality control level of tunnel construction is greatly improved; and a solid technical foundation is laid for safe, efficient and sustainable development of tunnel engineering.

The invention provides a high-temperature triggered directional self-repairing cement-based composite material and a preparation method thereof. The preparation method comprises the following steps: doping surface conductive modified thermal response type core-shell calcium carbonate whiskers into a cement system, wherein the thermal response type core-shell calcium carbonate whiskers are composed of calcium carbonate whisker cores and PNIPAM / nano-silica sol composite shells; in the sprayed concrete forming process, a vertical electric field system is arranged in a spraying track path or a lining support surface, acts on sprayed concrete and induces the PNIPAM / nano silica sol core-shell whiskers to be directionally arranged along a heat flux path, and a structure-enhanced concrete product A is formed; and finally, the product A is placed in a low-humidity and high-temperature environment with the temperature being 103-107 DEG C and the relative humidity being smaller than or equal to 10%, high-wind-speed drying pretreatment is conducted for 18-24 hours, then the same temperature and humidity conditions are maintained for wind-free maintenance till the age is 28 days, forming and performance maturation of the high-temperature self-repairing material are completed, and a final composite product B is obtained. The active crack resistance and high-temperature self-repairing performance of the material can be achieved.

The invention discloses a solid waste landfill crack combination self-repairing material based on microbial mineralization and application, and belongs to the field of environmental geotechnical engineering. The method comprises the steps that firstly, a klebsiella liquid and a calcium source cementing liquid are prepared, grouting holes are formed in the side slope, the bacterial liquid and the cementing liquid are injected in batches, and internal cracks are filled with a microorganism induced calcium carbonate precipitation (MICP) technology; and then, a fiber reinforced guniting material formed by compounding field soil, active magnesium oxide and chopped fibers is adopted to spray and cover the surface layer of the slope, and a compact sealing layer is formed through carbon dioxide carbonization. By combining internal MICP curing and surface layer fiber reinforced magnesium oxide carbonization sealing, a synergistic protection system with strong inside and tough outside is constructed, the anti-permeability and stability of the slope are improved, meanwhile, the toughness, crack resistance and long-term durability of a surface layer sealing layer are remarkably enhanced, and the service life of the slope is prolonged. And the method is particularly suitable for slope treatment of projects with high anti-seepage requirements such as solid waste landfills and the like.

The present invention relates to a setting accelerator composition for hardening a wet shotcrete formulation, comprising A1. Between 50% and 85% by weight of a cement containing at least 15% by weight of an aluminate, and A2. Between 15% and 50% by weight of at least one alkali metal sulfate.

The invention relates to the technical field of building materials, in particular to a shotcrete coagulating early strength agent and a preparation method thereof. Comprising the following components in percentage by mass: 45%-70% of sulphoaluminate cement clinker, 20%-45% of an early strength exciting material, 5%-15% of a nano reinforcing material, 3%-9% of a magnesium oxide expanding agent, 1%-3% of a retarding material, 0.8%-3% of a water retention material and 0.1%-1% of a dispersing agent. The coagulant early strength agent for sprayed concrete provided by the invention takes powder as a main material, can significantly improve the compressive strength of the sprayed concrete at an extremely early age, enables the compressive strength of the sprayed concrete at 3h to be greater than or equal to 1.2 MPa, the compressive strength of the sprayed concrete at 8h to be greater than or equal to 10MPa, the compressive strength of the sprayed concrete at 1d to be greater than or equal to 15MPa and the compressive strength of the sprayed concrete at 28d to be free from shrinkage, and is relatively convenient to transport and store, relatively good in stability and free from layering and caking problems; and the manufacturing process is relatively simple.

The utility model provides a slope protection pile foundation pit supporting structure which comprises a first step supporting structure and a second step supporting structure, the slope protection piles are arranged on deep foundation pit slope protection piles, the gradient of an upper slope of a deep foundation pit is 1: 4, and double rows of supporting piles are arranged at the deep foundation pit and are arranged in a step shape. The first step supporting structure is connected with the upper portion of the deep foundation pit through a second top beam, the bottom of the second top beam is connected with a supporting pile, and the supporting pile is connected with the second step supporting structure through a slope bottom ground beam, a row pile connecting beam and the first top beam in sequence. Concrete waist beams, anchor cables and drainage holes are arranged on the side surfaces of the support piles in the first step support structure and the second step support structure; a hanging net is arranged on the surface, connected with the supporting piles, from the top beam of the first step supporting structure to the slope bottom ground beam, a hanging net is arranged on the surface, connected with the supporting piles, from the first top beam of the second step supporting structure to the foundation pit base, and concrete is sprayed to the hanging nets. The slope protection pile foundation pit supporting structure is high in erosion resistance, and the gradient and displacement of a foundation pit can be effectively controlled.

The invention discloses an underground excavation station primary support arch cover method large arch springing structure and a construction method thereof, and aims at solving the technical problems that arch springing stress is concentrated in an upper-soft lower-hard stratum and traditional support settlement is large, and technical breakthrough is achieved through innovative combination of a dynamic adjustable support system and an intelligent grouting process. In the aspect of the structure, the self-adjusting steel pipe pile comprises inward inclination bottom feet with the inward inclination angle of 1: 6-8, a hinged angle adjusting base, a self-adjusting steel pipe pile with the dynamic adjustment of + / -5 degrees, a 600 * 600 * 25 mm partial pressure steel plate, a 45-degree inclined grouting hole channel, a check valve and a bottom longitudinal beam, a pile-plate-beam three-in-one structure is formed, and an optical fiber sensor is arranged in the steel pipe pile to monitor surrounding rock deformation in real time; according to the construction method, three-stage intelligent grouting, 0.1-0.3 MPa low-pressure filling, 0.5-0.8 MPa high-pressure reinforcing and compensation grouting based on monitoring are adopted, concrete is sprayed in cooperation with the telescopic formwork, and installation of the water stop type feet-lock anchor pipe and the water swelling rubber strip are completed synchronously.

The invention belongs to the technical field of building material additives and discloses a coagulant for sodium silicate excited slag sprayed concrete as well as a preparation method and application of the coagulant. The coagulant provided by the invention is prepared from the following raw materials in parts by mass: 45 to 60 parts of semi-hydrated gypsum, 25 to 35 parts of prehydrated Portland cement, 10 to 15 parts of gypsum whiskers and 10 to 15 parts of PCE-AFm nanoparticles. The coagulant can greatly shorten the coagulation time of the sodium silicate excited slag sprayed concrete, accelerate the hydration process and improve the mechanical properties of the concrete, so that the use amount of a gelling system exciting agent can be reduced, and carbon reduction is realized.

The invention belongs to the technical field of civil engineering materials, and particularly relates to sprayed concrete suitable for a chlorine salt erosion environment and a preparation method of the sprayed concrete. And meanwhile, the bionic helical carbon nanotube-polymer composite gel is pre-dispersed in water. Sequentially adding the aggregate, the fiber and the composite cementing material, carrying out dry mixing, adding the gel dispersion liquid, the water reducing agent and the air entraining agent, and stirring to obtain a mixture; and finally, adding an alkali-free liquid accelerator at a nozzle through a wet spraying process, and spraying the alkali-free liquid accelerator to a construction surface. The nano hybrid material can effectively adsorb and lock chloride ions, and the bionic gel has a crack self-repairing function. And the two components have a synergistic effect, and are combined with a compact microstructure and a fiber reinforcing and toughening effect, so that the obtained concrete has extremely high chloride ion penetration resistance and durability, and is particularly suitable for support and protection engineering in chlorine salt environments such as temporary expressways and the like.

The invention relates to the technical field of concrete admixtures, and discloses a composite admixture for reducing the springback rate of sprayed concrete and a preparation method of the composite admixture. The composite admixture comprises modified coconut fiber, silica fume, fluffy ash, a dispersing agent, cellulose ether, a polycarboxylate superplasticizer and an early strength agent, wherein relative to 100 parts by weight of the modified coconut fiber, the content of the silica fume is 75 to 85 parts by weight, the content of the fluffy ash is 35 to 45 parts by weight, the content of the dispersing agent is 6 to 10 parts by weight, the content of the cellulose ether is 5 to 9 parts by weight, the content of the polycarboxylic acid water reducing agent is 0.1 to 0.5 part by weight, and the content of the early strength agent is 0.03 to 0.07 part by weight; wherein the modified coconut fiber is a product obtained by modifying coconut fiber with rich hydroxyl groups on the surface by using a silane coupling agent. The composite admixture provided by the invention can effectively reduce the rebound rate of sprayed concrete, and maintains the compressive strength and durability of the concrete at the same time.

The application discloses a construction method of a soft foundation pit support and wall formwork. The method comprises the following steps: using cement mixing piles as the foundation pit support and wall outer formwork, constructing a shotcrete layer on the cement mixing piles, using the shotcrete layer as the outer wall formwork, drilling a rebar hole on the shotcrete layer, fixing an inner formwork through a full-thread water stop screw, pouring concrete in the inner formwork, and finally completing the wall construction of the underground space.

The application discloses a kind of segmented excavation construction methods combined with soil nailing wall support, belong to foundation pit support technical field, solve the technical problem that existing segmented excavation is difficult to control, and the safety risk caused by the sudden change of stress of supporting structure is caused by foundation pit deformation.It includes: dividing N excavation layers, setting each layer excavation depth and soil nail length;Layer by layer excavation, construction soil nail and shotcrete surface layer, and install displacement sensor and axial force sensor at the end of soil nail;After reaching the preset strength, read the cumulative horizontal displacement, current displacement rate and axial force increment;Compare with preset threshold respectively, if any is out of limit, then reduce the next layer excavation depth and increase the soil nail length, otherwise, construction according to original design parameters;Repeat until all excavation layers and support are completed.The application is mainly used for the segmented excavation construction of foundation pit in soft or sensitive stratum, can dynamically adjust the support parameters according to real-time monitoring data, effectively control the deformation of foundation pit, and improve the safety and adaptability of construction.

The concrete powder stable supply system comprises a conical tank body and a pressure pump, the tank body is sealed, the bottom of the tank body is connected with a control chamber, a rotator is arranged in the control chamber, the top of the tank body is provided with a pressure pipe, the bottom of the control chamber is connected with a driving pipe, and the driving pipe is connected with the pressure pump. An accelerator is loaded into the vacuum tank body, uniform pressure is applied through the pressurizing pipe, output of the accelerator is controlled, the accelerator can rotate uniformly through the rotator, and the accelerator can be conveyed to the control chamber through the pressurizing pipe, so that the accelerator can be conveyed to the control chamber, and the accelerator can be conveyed to the control chamber. The quantitative accelerator and pressurized gas output and input by the pressure pump are mixed and guided into the concrete through the mixing pipe, so that when the powdery accelerator is guided into the flow-state concrete pressure pipe of the sprayed concrete pouring device, the powdery accelerator can be quantitatively supplied, and the accelerator-transported concrete under the pressure can be uniformly distributed and stirred.

A coal-based solid waste regenerated aggregate shotcrete and a preparation method thereof, comprising cementitious material 100 parts, coarse aggregate 150-200 parts, fine aggregate 150-200 parts, polycarboxylate superplasticizer 2-4 parts, anti-adsorption agent 0.5-1.5 parts, water 35-60 parts, and defoaming agent 0.1-0.3 parts. The cementitious material is composed of cement and waste desulfurization gypsum; the coarse and fine aggregates are all coal gangue or gasification slag; the polycarboxylate superplasticizer is a slow-release polycarboxylate superplasticizer containing phosphate ester groups in the side chain; and the anti-adsorption agent is bentonite modified by a silane coupling agent. The modified bentonite anti-adsorption agent preferentially blocks the porous surface adsorption sites of the coal-based solid waste aggregate, and the slow-release polycarboxylate superplasticizer continuously provides dispersion force, effectively reduces the invalid consumption of the superplasticizer, significantly reduces the 1h slump loss rate of the concrete, reduces the rebound rate of the shotcrete construction to below 15%, and the total solid waste content is above 70%, realizing large-scale collaborative utilization of coal-based solid waste and waste desulfurization gypsum.