1350 results about "Shotcrete" patented technology

The invention relates to the technical field of tunnel engineering, in particular to an anti-collapse comprehensive treatment construction process for a tunnel to pass through a karst development area, which comprises the following steps: S1, early-stage exploration and planning: understanding a geological structure, karst development condition and underground water distribution along the tunnel in detail through drilling exploration, geological radar and seismic wave exploration; according to the anti-collapse comprehensive treatment construction process for the tunnel crossing the karst development area, the construction strategy is adjusted according to the actual geological condition, geological risks are treated more accurately, the construction progress is accelerated by adopting modern technologies and equipment such as geological radars, accidental interruption is reduced, comprehensive treatment measures are accurately controlled, and the construction efficiency is improved. The safety of the construction process is greatly improved, the influence on the surrounding environment is reduced, pollution is reduced by using environment-friendly materials and technologies, meanwhile, novel supporting materials and design are adopted in the construction technology, the novel supporting materials comprise a reinforcing mesh, anchor rods and sprayed concrete, immediate and lasting supporting is provided, and rock mass loosening and collapse are prevented.

The invention relates to the technical field of civil engineering, and particularly discloses a tunnel early-high-strength rock anchoring and shotcreting synergistic effect bearing arch active support design method which comprises the following steps: determining a rock anchor bearing arch acting load and establishing a rock anchor bearing arch calculation model; calculating to obtain the most unfavorable section displacement and stress of the rock anchor bearing arch; verifying whether the displacement of the rock anchor bearing arch meets the requirement; a safety evaluation method of the pre-stressed anchor rods is provided, and the safety of the pre-stressed anchor rods is evaluated according to a rock anchor bearing arch calculation result; establishing a sprayed concrete calculation model; calculating to obtain the most unfavorable section displacement and stress of the sprayed concrete; a sprayed concrete safety and durability evaluation method is provided; active support parameters are determined according to the calculation result of the rock anchor bearing arch and the calculation result of the sprayed concrete. By means of the method, the safety and durability of rock-anchor-shotcrete active supporting under different supporting parameters can be simply, rapidly and accurately calculated, reference is provided for tunnel engineering design adopting active supporting, and good engineering value is achieved.

The invention provides a sprayed concrete hardening detection method and system, and relates to the technical field of material detection.The sprayed concrete hardening detection method comprises the steps that detection requirements are determined based on physical characteristics of sprayed concrete, and a progressive multi-frequency excitation sequence is established; after each time of multi-frequency excitation is completed, echo signals in the concrete are monitored in real time, and excitation parameters are dynamically adjusted according to the quality of the echo signals; the collected echo signals are preprocessed; performing multi-dimensional characteristic parameter extraction on the preprocessed echo signals, including time domain characteristics, frequency domain characteristics and energy domain characteristics, to form representative characteristic vectors; removing redundant features according to the feature vector, and calculating a hardening score by using residual features; and outputting a detection result and early warning information according to the hardening score. According to the method, the hardening state of the sprayed concrete can be accurately evaluated, so that reliable technical support is provided for engineering construction quality control.

The invention discloses recycled coarse aggregate early-strength low-resilience sprayed concrete and a preparation method thereof, and belongs to the technical field of building materials. The recycled coarse aggregate early-strength low-resilience sprayed concrete is prepared from the following components in parts by weight: 450 to 500 parts of cement, 800 to 910 parts of fine aggregate, 800 to 920 parts of coarse aggregate, 15 to 25 parts of an exciting agent, 160 to 190 parts of water, 4.5 to 10 parts of a water reducing agent and 27 to 45 parts of an accelerator, the used coarse aggregate is regenerated hardened concrete, and the exciting agent is a special material. The recycled coarse aggregate early-strength low-resilience shotcrete provided by the invention is high in cohesiveness, strong in cohesion and high in early strength, is more easily adhered to the surface of surrounding rock when being sprayed to tunnel surrounding rock or a side slope, is not easy to fall off, and is low in resilience rate.

The invention discloses a portal type integrated operation workstation capable of adapting to different underground cavern sections. The portal type integrated operation workstation comprises a frame supporting system, an intelligent control room, a moving walking system, an electrical system and a functional arm system. The frame supporting system comprises first longitudinal beams which are arranged in a left-right spaced mode, and a plurality of transverse telescopic joints are installed between the left first longitudinal beam and the right first longitudinal beam. A plurality of longitudinal shrinkage joints are mounted at the lower end of each first longitudinal beam, the lower ends of the longitudinal shrinkage joints are connected with a high-strength supporting frame, and a movable walking system is mounted at the bottom of the high-strength supporting frame; the functional arm system comprises a concrete spraying-arch mounting arm, an anchor rod mounting arm and a drilling arm which are arranged in a layered mode from top to bottom. According to the portal type integrated operation workstation capable of adapting to different underground cavern sections, the functions of drilling, anchor rod construction, grouting, net hanging, arch frame installation, spraying and mixing and the like are integrated, and meanwhile the size of equipment can be freely adjusted so that the portal type integrated operation workstation can adapt to the extra-large sections of different sizes.

The utility model discloses a tunnel repairing system, a trolley and a heading machine, the tunnel repairing system comprises a detection module, a breaking module and a repairing module which are arranged in sequence, and the detection module, the breaking module and the repairing module all have the degree of freedom of axial stretching and the degree of freedom of circumferential rotation; the trolley comprises the tunnel repairing system. The heading machine comprises the trolley. The detection module can detect the inner wall of a tunnel, the breaking module can break the surface layer and the edge of an area needing to be repaired according to the detection result of the detection module, and the repairing module can automatically repair the area broken by the breaking module. According to the technical scheme, the tunnel can be monitored in a full range, detection data of each position can be recorded in real time, the data are analyzed by the processor in a unified mode, human intervention is not needed, hole wall clearing and guniting repairing can be automatically completed when a fault area is found, the detection efficiency and the detection quality can be guaranteed, and the influence of human factors on a detection result is avoided.

The invention relates to the technical field of concrete construction, and discloses a method for reducing the concrete spraying rebound rate and a concrete wet spraying device.The method comprises the following steps that a fluid control model based on historical guniting data is established, the model is used for performing parameter matching on the concrete guniting volume and the spraying speed, the spraying pressure and the spraying temperature of the high-speed fluid; the real-time guniting volume of the concrete wet spraying equipment is collected; and according to the guniting volume and the control model, generating fluid jet control parameters matched with the guniting volume and the control model. And through an accurate fluid control model and a real-time feedback mechanism, the concrete spraying rebound rate is effectively reduced. And an automatic spraying parameter adjusting mechanism is adopted, so that the pressure, the angle and the spraying amount of the sprayed fluid are accurately adjusted according to real-time monitoring data, and the construction efficiency and the spraying consistency are improved. And through a high-precision rebound rate monitoring system, rebound data are automatically calculated and fed back, the spraying process is optimized, concrete waste is reduced, and the resource utilization rate is increased.

The invention discloses early-strength, low-resilience and high-durability sprayed concrete and a preparation method thereof. The sprayed concrete is prepared from the following components: cement, an early-strength hardening auxiliary cementing material, coarse aggregate, fine aggregate, water, an additive, a fluoride-free alkali-free high-concentration accelerator, a rheology modifier, fibers and the like. The preparation method of the sprayed concrete mainly comprises two aspects. The method comprises the following steps: (1) proportioning optimization; and (2) functional materials are applied. By optimizing the glue material amount, the water-glue ratio and the sand ratio and adopting the small-particle-size coarse aggregate, the concrete has good workability and homogeneity, the risk of pipe blocking in the pumping and spraying process is reduced, aggregate rebound in the jet flow process is reduced, and the spraying operation effect is optimized. By applying the high-concentration fluoride-free alkali-free accelerator and the early-strength hardening auxiliary cementing material, the early strength of the concrete can be effectively improved, the volume deformation is reduced, and the long-term mechanical property and durability are improved. The fiber and the rheological modifier are added, so that the rheological property of the sprayed concrete can be further effectively improved, and the rebound rate is reduced. Rapid setting of the sprayed concrete and cooperative improvement of mechanical properties and long-term performance are achieved by optimizing the mixing ratio and applying novel functional materials.

The invention discloses a low-shrinkage high-toughness sprayed concrete material as well as a preparation method and application thereof, and the low-shrinkage high-toughness sprayed concrete material is prepared from the following materials in parts by mass: 400 to 440 parts of cement, 50 to 70 parts of coal ash, 20 to 40 parts of silica fume, 170 to 190 parts of water, 850 to 880 parts of fine aggregate, 770 to 810 parts of coarse aggregate, 30 to 50 parts of accelerator and 3.2 to 6.0 parts of water reducing agent. Hybrid fibers: 30 to 50 parts of steel fibers and 0.9 to 2.7 parts of organic fibers. The low-shrinkage high-toughness sprayed concrete material provided by the invention can ensure high compressive strength and toughness, also has good durability and stability, effectively improves the construction quality of tunnel engineering, and has very excellent market prospects.

The invention relates to the technical field of hydraulically-driven industrial control, and particularly discloses a self-adaptive control method and system for a hydraulically-driven guniting manipulator, which are characterized in that a pressure fluctuation signal, a flow change signal and a mechanical arm displacement signal of a hydraulic system are collected in real time, and a frequency domain decomposition processing technology is combined to realize self-adaptive control of the hydraulically-driven guniting manipulator. Separating the composite signal into a low-frequency characteristic signal reflecting load change and a high-frequency characteristic signal reflecting pressure impact; for a low-frequency signal, a dynamic weight adjustment strategy is adopted to generate a load compensation control quantity; for high-frequency signals, pressure oscillation is suppressed through differential order adjustable phase compensation processing; and finally, inputting the two paths of control characteristic values into a driving control model of the guniting manipulator, and generating an adjusting instruction of the hydraulic actuating mechanism.

The invention discloses a low-carbon high-compactness shotcrete elasticity reducing agent and a preparation method and application thereof, and relates to the field of building material concrete admixtures, the elasticity reducing agent comprises the following components by mass: 53-73% of a rheological component, 15-25% of a tackifying component, 10-18% of an early strength component, and 0.5-4% of a setting adjusting component; the rheological component comprises manganese slag powder and silica fume, and the tackifying component is tailing powder loaded with nano modified cellulose ether. The viscosity of sprayed concrete is increased through the tackifying component, the slurry wrapping property of the concrete is improved, the yield stress of the concrete is improved through the rheological component, and the early strength component is combined to synergistically improve the wall-adhering and quick-hardening properties after the material is sprayed, so that the rebound rate is reduced; the nano-particles loaded on the organic matter are hydrated in pores, harmful pores are directionally filled, the compactness and strength of the sprayed concrete are effectively improved, and low-carbon, low-resilience and high-compactness of the sprayed concrete are achieved.

The invention discloses wet shotcrete for tunnel engineering as well as preparation and application methods thereof, and belongs to the technical field of wet shotcrete. The wet spraying concrete for tunnel engineering is characterized by being prepared from the following components in parts by weight: 410 to 440 parts of cement, 850 to 980 parts of medium sand, 780 to 860 parts of coarse aggregate, 195 to 215 parts of water, 35 to 45 parts of coated modified porous aggregate, 9 to 13 parts of water reducing agent and 12 to 25 parts of accelerator. The porous aggregate is subjected to coating modification treatment, so that in the preparation and production process of the wet-sprayed concrete for tunnel engineering, the state of the concrete is not influenced, but in the concrete spraying process, due to the fact that the porous aggregate subjected to coating modification and a film coated by the porous aggregate are damaged under the action of pumping and pumping pressure, the wet-sprayed concrete for tunnel engineering is not influenced. The porous aggregate is exposed, and the porous aggregate can adsorb free water in the concrete due to the characteristics of porosity and extremely easy water absorption of the porous aggregate, so that the concrete becomes viscous during spraying, and the rebound rate of the concrete is reduced.

The invention belongs to the technical field of tunnel construction, and discloses SAP geopolymer sprayed concrete and application thereof in primary lining of a high-ground-temperature tunnel. The concrete is prepared from the following raw materials in parts by mass: 100 parts of a cementing material, 13-16 parts of an alkali activator, 135-150 parts of river sand, 165-185 parts of stones, 32-41 parts of water and a proper amount of SAP, in percentage by mass, the use amount of the SAP is 0.2-0.3% of the binding material; the cementing material is composed of slag and fly ash according to a mass ratio of (0.24-0.26): 1. The SAP geopolymer sprayed concrete is applied to primary lining of a high-ground-temperature tunnel. The SAP geopolymer shotcrete not only has high strength and high toughness of traditional shotcrete, but also has good heat insulation and heat resistance, has supporting and heat insulation performance, realizes environment-friendly and pollution-free construction, and is particularly suitable for high-ground-temperature tunnels and the like.

The invention relates to the field of sprayed concrete, in particular to green low-carbon high-performance sprayed concrete using active regenerated micro powder and a preparation method and a construction process of the green low-carbon high-performance sprayed concrete. The sprayed concrete is prepared from the following components in parts by weight: 300 to 350 parts of cement, 50 to 80 parts of active regenerated micro powder, 60 to 120 parts of early strength type mineral admixture, 20 to 40 parts of rubber powder, 10 to 20 parts of hydrophobic compacting agent, 700 to 800 parts of coarse aggregate and 800 to 900 parts of fine aggregate, the mixing amount of the water reducing agent is 0.8%-1.2% of the mass of the cementing material, and the mixing amount of the fluoride-free alkali-free accelerator is 6%-9% of the mass of the cementing material; wherein the active regenerated micro powder is composed of multi-component isomeric alcohol amine and regenerated micro powder, and the dosage of the multi-component isomeric alcohol amine is 0.1%-0.5% of the mass of the cementing material. The cement consumption of the sprayed concrete can be reduced, and the requirement for high performance of the sprayed concrete is met.

A dynamic monitoring method for a rebound rate of wet spraying shotcrete includes converting a set of laser points obtained from scanning to a rock wall scanning surface relative coordinate system to form an initial geometric model of the rock face, calculating the initial rock wall volume, coarse spraying and fine spraying the shotcrete and performing the three-dimensional modeling calculations, and calculating the coarse spray rebound rate and the fine spray rebound rate, thereby solving the problem that at present, the estimated idealized data does not match the actual usage data, not only it is insufficient in quantification, but also the dynamic rebound rate of the wet spraying process is not understood, in which the rebound rate is inaccurately estimated, making it difficult to guide the adjustment of the shotcrete formula and the adjustment of the spray posture and speed, and thus the goal of process optimization cannot be achieved.

The invention particularly discloses a time-space design method for a railway tunnel active support rock anchoring and shotcreting synergistic effect considering a time-space effect, and relates to the technical field of civil engineering. The method comprises the steps that firstly, expression characteristics of the load time effect, the material time effect, the tunnel face space effect and the rock anchor bearing arch space effect of active supporting are determined, a space-time effect characterization method is established, and then a tunnel active supporting rock anchor and shotcrete synergistic effect space-time calculation model is constructed; then determining calculation parameters of a rock anchor bearing arch and a sprayed concrete layer, and constructing a surrounding rock pressure calculation method and a safety evaluation method considering the advance support effect; and finally, according to a calculation result of the tunnel active support rock anchoring and shotcreting synergistic effect space-time calculation model, safety is judged, and design parameters of a pre-stressed anchor rod and shotcreting concrete are determined. The method can simply, quickly and accurately calculate the internal force distribution and safety of the tunnel rock anchor bearing arch and the sprayed concrete layer under different time, geological conditions and support design parameters, and has good engineering value.

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 relates to the technical field of concrete preparation, in particular to a modified imitation steel fiber toughened sprayed concrete material and a preparation process thereof.The modified imitation steel fiber toughened sprayed concrete material is prepared from, by weight, 400-420 kg / m < 3 > of cement, 175-190 kg / m < 3 > of water, 820-840 kg / m < 3 > of coarse aggregate, 890-910 kg / m < 3 > of fine aggregate, 32-40 kg / m < 3 > of silicon powder, 6.5-7 kg / m < 3 > of water reducing agent, 25-30 kg / m < 3 > of accelerator and 3-5 kg / m < 3 > of modified imitation steel fiber; the modified imitated steel fiber is formed by mixing sulfonated polypropylene imitated steel fiber and carboxylated polypropylene imitated steel fiber according to the mass ratio of 1: (1.2-1.8). The modified steel-imitating fiber is prepared by sulfonating and carboxylating the polypropylene steel-imitating fiber and reasonably compounding, and is applied to a sprayed concrete material, so that the adhesive property of the sprayed concrete can be obviously improved, the rebound rate of the sprayed concrete can be obviously reduced, and the mechanical property of the sprayed concrete can be effectively improved.

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.

To provide a setting method of an approximate equation of an equivalent elastic modulus of spray concrete, capable of identifying an equivalent elastic modulus of the spray concrete with accuracy in which actual phenomenon can be reflected, and a design method of timbering of a mountain tunnel.SOLUTION: A setting method of an approximate equation of an equivalent elastic modulus of spray concrete, comprises: an A step for performing multi-stage stress relaxing test, to a sample of the spray concrete; a B step for executing reproduction analysis for reproducing a stress-time relationship; a C step for executing successive digging analysis of the tunnel; and a D step for setting an equivalent elastic modulus, from a stress-strain relationship of a spray concrete model which is determined by the digging analysis of the tunnel. In the C and D steps, to at least one of parameters formed of a tunnel diameter, an elastic coefficient of natural ground, a cycle time, and intensity of the spray concrete, the successive digging analysis of the tunnel is executed by parametric study, and on the basis of the analysis result, an approximate equation of the equivalent elastic modulus being at least one function in parameters, is created.SELECTED DRAWING: Figure 1

The invention relates to the technical field of concrete admixtures, and discloses a nano rebound inhibitor for shotcrete and a preparation method thereof. The components, measured by weight, include 400-600 parts of nano microspheres, 400-550 parts of nano calcium carbonate, 10-30 parts of sodium carbonate, 1-10 parts of sodium aluminate, 10-30 parts of alum, 18-40 parts of polycarboxylic acid water reducer, and 0-0.5 parts of triterpenoid saponin; the nano microspheres are hydrated calcium silicate with silicon dioxide as the core material and colloid as the shell material, and the colloid is doped with a lithium source. The nano rebound inhibitor of the present application can significantly improve the state of shotcrete and greatly reduce the rebound amount of concrete, thereby further saving construction costs and accelerating construction accuracy. By utilizing the characteristics of the mineral admixture in the nano rebound inhibitor, the compactness of the concrete can be improved, and the durability of the shotcrete can be further improved.

The invention belongs to the technical field of tunnel supporting, and discloses a supporting structure of a long-distance deeply-buried TBM inclined shaft water-rich complex rock stratum and a working method.The supporting structure comprises graded yielding control anchor rods, anchor cables, a steel bar row, a steel bar net and a sprayed concrete layer, and the steel bar row, the steel bar net and the sprayed concrete layer are sequentially arranged on the tunnel surrounding rock surface from outside to inside; the graded yielding control anchor rod comprises a rod body, an outer ring, a yielding sleeve and an inner ring. In an initial state, the rear end of the rod body presses the inner ring on the rear port of the inner cavity of the yielding sleeve through a nut; the front end of the yielding sleeve extends into the drill hole and tightly presses the outer ring on the surrounding rock on the outer side of the drill hole; primary yielding friction fit is formed between the inner ring and an inner cavity of the yielding sleeve; and the front end of the yielding sleeve is in secondary yielding friction fit with the outer ring. The method has the advantages that the bearing capacity of the surrounding rock is fully exerted, and passive support is converted into active support; the graded yielding control anchor rods and the anchor cables are jointly supported, and the supporting structure is good in integrity and high in strength.

The invention relates to the technical field of concrete preparation, in particular to sprayed concrete with high crack resistance and low rebound rate and a preparation method thereof. The nano aerogel, the polypropylene fiber and the modified vermiculite are creatively adopted to prepare the sprayed concrete, and the nano aerogel has the water retention and moisture absorption characteristics and plays an internal curing role in the concrete, so that the internal water loss rate is reduced, the shrinkage of the concrete is weakened, and the concrete is prevented from being damaged. Meanwhile, the polypropylene crude fiber with high breaking strength and elasticity modulus and a composite cross-linked network structure formed by the polypropylene crude fiber and the modified vermiculite can greatly improve the crack resistance and durability of the sprayed concrete under the interaction; furthermore, when the concrete is cracked, the modified liquid flows out of the inner cavity of the vermiculite and is adhered and cured at the crack to realize a self-repairing effect, so that the structural deformation of the tunnel can be better limited, and the service life of the tunnel lining in a complex environment is prolonged.

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 present invention discloses a high-performance shotcrete and a preparation method thereof, belonging to the technical field of shotcrete. The concrete comprises the following components by weight: 430-450 parts of cement, 800-850 parts of coarse aggregate, 850-900 parts of fine aggregate, 170-180 parts of water, 4-5 parts of a water reducer, 34-41 parts of an early-strength accelerator, 4-8 parts of a solidifying and durable component, and 1.0-1.4 parts of polypropylene fiber. A corresponding preparation method is also provided. The present invention achieves high performance shotcrete by selecting an early-strength accelerator and a solidifying and durable component and optimizing the preparation method. This can effectively reduce rebound, promote rapid development of early strength, and fully guarantee the long-term durability of shotcrete. Its application in tunnel engineering can significantly improve the performance of shotcrete, thereby improving the quality of the engineering structure and fully guaranteeing the service safety of tunnel engineering, thus having broad prospects.

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 construction method for prefabricating and assembling a seabed energy storage tank through prestress, and belongs to the technical field of structural engineering. The energy storage tank comprises a plurality of sub-spherical shell units and prestressed reinforcements. The construction method comprises factory prefabrication and field assembly processes of the plurality of sub-spherical shell units. The sub spherical shell units are made of common concrete or ultra-high performance concrete or ultra-high toughness concrete, PVC or metal corrugated pipes used for allowing prestressed steel bars to penetrate through are pre-buried in the shell framework, and anchorage device positioning grooves are reserved in the edges of the shell framework. A plurality of sub spherical shell units are sequentially spliced on site, high-strength prestressed steel bars are arranged in a pipeline in a penetrating mode and are tensioned in a segmented mode, anchorage devices are installed at the ends of the steel bars for fixing, and an overall spherical structure is formed. And sprayed concrete materials are applied to the joints and the positioning grooves for sealing, so that a closed energy storage spherical tank structure is formed. The method is suitable for an energy storage system in a deep sea high-pressure environment, and has the characteristics of simple and convenient construction process and good structural integrity and water tightness.

The invention discloses a component-level digital twin railway tunnel engineering three-dimensional model three-dimensional tile conversion method, which comprises the following steps: opening a tunnel BIM model file, and obtaining external setting parameters, artificial constraint parameters and model information to generate triangular mesh model data; establishing an association relationship between the semantic attribute information and the triangular mesh model, and mapping one by one to obtain LOD4 hierarchical model data; screening and cleaning the semantics, and removing a specified component to obtain LLO3 hierarchical model data; obtaining a maximum outer bounding box fitting elliptic cylinder of the tunnel model, and performing similar block replacement to obtain LOD2 hierarchical model data; the method comprises the following steps: traversing sprayed concrete members according to a line trend sequence to obtain coordinates of geometric center points of bounding boxes of the sprayed concrete members, and forming an ordered point set fitting line as an LOD1 hierarchical model; performing format conversion on the LOD models of different hierarchies, and finally organizing the LOD models into a tree structure to form three-dimensional tile structure data; the method is simple and high in execution efficiency.

The invention provides a nano C-S-H crystal nucleus early strength agent and a preparation method thereof, and relates to the technical field of concrete admixtures. The nano C-S-H crystal nucleus early strength agent is prepared from the following raw materials in parts by weight: 100 to 150 parts of dispersing agent, 300 to 400 parts of water, 10 to 20 parts of NaOH aqueous solution, 0.1 to 1 part of defoaming agent, 200 to 400 parts of Ca (NO3) 2.4 H2O aqueous solution and 150 to 350 parts of Na2SiO3. 5H2O aqueous solution. The nano C-S-H crystal nucleus early strength agent provided by the invention can effectively improve the early strength of concrete whether being applied to early strength sprayed concrete or duct piece concrete.