42 results about "Liquefaction resistance" patented technology

The invention discloses a method for treating liquefiable sandy soil foundations by using microbial bubbles, mainly targeting at liquefiable sandy soil layers, using liquid injection nozzles, hollow drill pipes, connectors, catheters, compressors, bacterial liquid storage tanks, etc. The device injects pre-enriched and cultured denitrifying bacteria liquid into the soil to replace pore water, and the bacteria perform denitrification in the pores to produce inert gases nitrogen and carbon dioxide. The nitrogen produced by biological metabolism in the pores can effectively reduce the soil saturation, increase the shear strength of the soil, and improve the soil's ability to resist liquefaction. Nitrogen dioxide produced by biological metabolism can induce the precipitation of calcium ions in the bacterial fluid to form calcite. Calcite has strong cementing properties, which can effectively improve the cohesion between soil particles, increase the shear strength, and can fill the pores of the soil, increase the compactness of the soil, and further improve its ability to resist liquefaction.

A liquefaction resistance foundation stabilization method by grate hooping belongs to the field of building and specifically is a foundation treatment method. Cement piling wall grates are made in a foundation to hoop soil under the foundation, and the foundation is separated into a plurality of enclosed grids. By the aid of the liquefaction resistance foundation stabilization method by grate hooping, integral strength and rigidity of the foundation are improved greatly, and meanwhile most of shearing strength generated by earthquake load is shared by the cement hoop piling walls to limit foundation deformation greatly, so that hyperstatic pore water pressure of saturated sand and floury soil in the grids is restrained effectively, and a great liquefaction resisting function is achieved.

The invention discloses a gravel pile composite foundation liquefaction resistance distinguishing method based on a super-pore water pressure ratio. The method comprises the following steps that by means of the relation between a liquefaction index and the field super-pore water pressure ratio, on the basis of the field super-pore water pressure ratio of the gravel pile composite foundation, an equivalent liquefaction index of the composite foundation is obtained; according to the magnitude of the equivalent liquefaction index of the composite foundation, the liquefaction grade of the gravel pile composite foundation is evaluated according to the existing code for seismic design of buildings, and the problem that only compaction and vibro-compaction effects of a gravel pile are reflected for the distinguishing standard of the standard penetration method of gravel pile composite foundation liquefaction resistance in the existing code for seismic design of buildings is solved; the compaction and vibro-compaction effects, damping effects and drainage pressure reduction effects of the gravel pile are comprehensively considered; in the actual engineering, the distinguishing standard is applied, the design scheme of the gravel pile composite foundation can be more reasonable, foundation processing workloads can be reduced, the construction period can be shortened, the engineering investment can be saved, and the good application prospect is achieved.

The invention discloses a liquefiable foundation device for micro-nano bubble processing and an operation method. In terms of a liquefiable sand layer in a foundation, a mixture of micro-nano bubbles and water is injected through a micro-nano gas-liquid mixture generator, a compressor, an air guide pipe, a hollow drilling pipe, a gas sprayer and the like, the micro-nano bubbles can stay in soil for a long time, the saturation is reduced, shearing strength of the soil is enhanced, and accordingly liquefaction resistance of the liquefiable sand layer is remarkably improved. When the liquefiable sand layer bears a vibration load, gas left in the soil can serve as a buffering agent and effectively buffer the tendency that pore water pressure rises, and accordingly the liquefaction resistance of the foundation is improved.

The invention discloses a stirring pile-permeable concrete pile compound foundation, which comprises a plurality of rows of stirring piles and permeable concrete piles, wherein the stirring piles and the permeable concrete piles are arranged in a row spacing way; and a gravel cushion layer is paved on the surface of the foundation on the upper parts of the stirring piles and the permeable concrete piles. The invention discloses a method for treating the foundation simultaneously. The compound foundation has high bearing capability and high permeability, post-construction settlement can be effectively reduced, and the liquefaction resistance of the foundation can be improved. Meanwhile, under the action of drainage consolidation, the compound foundation can be used for eliminating engineering diseases caused by stirring pile construction.

The invention provides a deep saturated sand earthquake-induced liquefaction judgment method, which comprises six steps: 1) determining standard penetration numbers of a deep saturated sand layer at different positions and in different depths; 2) determining seismic cyclic shear stress ratio CSR of different standard penetration test points of the deep saturated sand layer; 3) determining actual critical overlying effective stress of standard penetration test through a hypothetical test method; 4) obtaining normalized standard penetration numbers of the different standard penetration test points at different positions and in different depths; 5) determining liquefaction-resistance cyclic shear stress ratio CRR7.5; and 6) making a comparison between the seismic cyclic shear stress ratio CSR and the liquefaction-resistance cyclic shear stress ratio CRR7.5, and carrying out earthquake-induced liquefaction judgment. The method can overcome the defect that a standard penetration number liquefaction judgment method in the current specifications cannot be applied to the soil layer, the depth of which is larger than 20m, and can enable the existing standard penetration number liquefaction judgment method to be expanded and applied to deep saturated sand earthquake-induced liquefaction judgment.

The invention discloses an ABAQUS-based soil foundation liquefaction research method which is suitable for the problem of design analysis of liquefaction grounds in civil and hydraulic engineering. The research method is characterized in that 1) numerical simulation in ABAQUS of the soil foundation seismic liquefaction process is realized based on a Byrne liquefaction model and through secondary development of ABAQUS finite element software; 2) for a horizontal ground, a computation formula of liquefaction effect reduction factor continuity is given by utilizing the numerical model and the analysis process above, thereby solving the problem of large jump of "gear" valuing of liquidation effect coefficient of the horizontal ground at present; and 3) for inclined grounds, a correspondence relationship between liquefaction-resistance indexes of the inclined grounds with different inclination angels and excess pore water pressure is given by utilizing the numerical model and the analysis process above. The method states when a liquefaction judgment method in the current standard is applied to the inclined grounds, the liquefaction judgment method needs to be corrected, and a correction method is provided.

The invention discloses a method for measuring liquefaction resistance of offshore submarine sediments in situ. In the method, a measuring device is provided. The measuring process comprises a layingstep and a data acquisition step, in the laying step, S1, transporting the measuring device to a research target point position by an auxiliary boat, enabling a data module to work, connecting a lifting device with the measuring device through a mooring rope and a controllable hook, lifting the measuring device to a position above the research site position and keeping the measuring device to be vertical; S2, opening the controllable hook to enable the measuring device to penetrate into the offshore submarine sediments under the action of free gravity; in the recovering step, S3, after the measuring device penetrates into and is stable, recovering the measuring device through the lifting device; S4, acquiring penetration depth data and accelerated speed data. According to the method, the advantages of in-situ measuring methods such as SPT and CPT are synthesized, the liquefaction resistance of the offshore submarine sediments can be measured and evaluated effectively, and accurate dataand research basis are provided for prevention and control of coastal zone geological disaster.

The invention belongs to the field of geotechnical engineering and relates to a prefabricated concrete square drainage pile for liquefaction resistance of foundation soil. According to the pile, vertical cavities are symmetrically formed in side surfaces of a prefabricated concrete square pile, porous aluminium alloy buckle plates are used for enclosing, and porous areas are covered with water filtering type geotextiles. Limitations that discrete material piles are insufficient in strength and rigid piles cannot drain water in the liquefied foundation soil reinforcing process are broken through. The pile comprises the prefabricated concrete square pile, the porous aluminium alloy buckle plates and the water filtering type geotextiles, all components can be produced in factories in batches, and the pile is simple in structure, high in pile body strength and good in drainage effect.

The invention relates to a curing agent for treating a deep soft foundation soil layer and a preparation method thereof. The curing agent consists of metal oxides with activity of Al2O3, Fe2O3, CaO and MgO, nonmetal oxides with activity of SiO2 and SO3, and an acyclic sulfonate water-reducer. The preparation method for the curing agent comprises the following steps of: drying the metal oxides andthe nonmetal oxides in a dryer, and heating at the temperature of between 750 and 850DEG C for 3 to 4 hours; grinding into granules that the residue of a 80 mu m square sifter is not more than 4.0 percent by using a ball mill; and adding the acyclic sulfonate water-reducer and uniformly stirring to obtain the curing agent for treating the deep soft foundation soil layer. The curing agent can makethe unconfined compressive strength, deformation, permeability, liquefaction resistance and other properties of the treated soft foundation soil body obviously improved.

The invention relates to a deformable silt liquefaction-resistant drainage device. The device comprises two soft water permeable devices which are buried in a silt layer in parallel, wherein the bottoms of the soft water permeable devices are coated with a geotechnical fabric; a gravel reverse filtering layer and a water pump are arranged inside the two soft water permeable devices; the water pumpis located above the gravel reverse filtering layer; the water pump is connected with a water pumping pipe; and the water pumping pipe extends to the position above the silt layer. According to the deformable silt liquefaction-resistant drainage device and a using method thereof, the consolidation of the soil body can be accelerated; a certain soil pressure can be borne in the radial direction soas to keep a pipe well stable; the device can be vertically deformed to be coordinated with the foundation deformation; and discharging of the super-gap water pressure can be accelerated when the soil body encounters a vibration load, and thus the liquefaction resistance of the silt is improved.

The invention belongs to the technical field of soil body stability research and discloses a hollow anti-slip anti-liquefaction pile, comprising a pile body, cuboid protrusions, a water storage tank,a water pumping hole and water guide holes. A plurality of cuboid protrusions are evenly distributed along the periphery of the pile body. Water storage tanks are respectively formed in the outer sides of the cuboid protrusions, filter screens are arranged on the outer sides of the water storage tanks respectively, the water pumping hole is formed in the center of the pile body, the water storagetanks communicate with the water pumping hole through the water guide holes respectively, a plurality of through hole channels are formed in the pile body, a pile head is fixed to the bottom of the pile body, and the cuboid protrusions, the water storage tanks and the water pumping hole are parallel to a shaft of the pile body. The hollow anti-slip anti-liquefaction pile has the characteristics ofdrainage and liquefaction resistance, the outer sides of the cuboid protrusions on the periphery of the pile body are provided with the water storage tanks, the water storage tanks are covered with the double-layer stainless steel filter screens, so as to prevent the filter screens from being blocked when large-particle-size blocks in soil pass through, and water in the water storage tanks is guided into the water pumping pipe through the water guide holes formed in the pile body and then is pumped out by a water pump in a unified mode.

The invention provides a construction method of engineering foundation pre-soaking dynamic consolidation. The construction method includes the following steps that 1, the construction range is determined, and the thickness of blow filling sand is measured; 2, sites and the number of laid plastic drainage plates in the construction range are determined, and the arranged depth of the plastic drainage plates is determined; 3, the plastic drainage plates are laid, and a blow filling sand foundation is subjected to vibroflotation and drainage through a conventional vibroflot; 4, water with the preset water yield is sprayed into the construction range of the blow filling sand foundation by prefabricated pre-soaking ramming equipment so as to maintain the preset water content of the blow fillingsand foundation, then dynamic consolidation is carried out by the pre-soaking ramming equipment, and fixed point spraying of ramming points is carried out by the pre-soaking ramming equipment in the process of dynamic consolidation so as to ensure no dust; and 5, the foundation bearing capacity and liquefaction resistance performance are detected. According to the construction method of engineering foundation pre-soaking dynamic consolidation, the problems that the quality of dynamic consolidation and subsequent vibration rolling construction is affected and the environment is polluted due tothe fact that a surface layer is difficult to be compacted in the treatment process of the existing blow filling sand foundation are effectively solved.

The invention relates to a method of liquefaction resistance processing of filament reinforced sandy soil. The method comprises the first step of preparation of raw materials, wherein polypropylene filaments or polyethylene filaments or polyurethane filaments or polyester filaments are adopted as filaments, the adulterate amount of the filaments is 0.2-0.8% of the weight of dry sandy soil, the dry sandy soil is siliceous sand, the grain diameter is 0.074-2mm, the specific gravity of the dry sandy soil is 2.65, the maximum dry density is 1.6g / cm, the sandy soil and water are fully stirred evenly, and then wet sandy soil of the water content being 10-15% is obtained; the second step of blending of the raw materials, wherein firstly the filaments prepared in the first step are fully dispersed through manpower or a small air blower, then the dispersed filaments and the wet sandy soil prepared in the first step are fully blended, the blending time is 20-30min, and finally the obtained material is compacted in a layered mode to form finished filament reinforced sandy soil. The method of the liquefaction resistance processing of the filament reinforced sandy soil can meet the requirements for liquefaction resistance of embankment projects such as side slopes, roadbeds, embankment foundations and banks under the condition of dry and wet circulation.

The invention discloses a treatment method for a hydraulic structure foundation. The treatment method comprises the following steps that 1, a foundation trench is excavated at the mounting position of a hydraulic structure on a seabed, and undisturbed sand with enough thickness is reserved at the bottom of the foundation trench; 2, sand is thrown into the foundation trench until the replacement and filling sand in the foundation trench reaches the designed elevation; 3, a crawler crane is placed on a flat barge; 4, a vibroflot is adopted for carrying out vibroflotation reinforcement on the foundation of a foundation bed, the vibroflotation width is the sum of the bottom width of the foundation trench and the two sides expanded outwards by 5 m, and the vibroflotation thickness is the bottom elevation from the design elevation of the replacement and filling sand in the foundation trench to the undisturbed sand; and 5, the surface layer of the foundation bed is tamped and reinforced by adopting a rammer. According to the treatment method, the combined treatment mode of a vibroflotation method and a dynamic compaction method is adopted, the surface layer quality of the treated foundation can be greatly improved, the overall treatment effect of the foundation can be improved, and the strength and impermeability and liquefaction resistance of the treated foundation are improved.

The invention relates to a foundation treatment method and a foundation treatment structure. The foundation treatment method comprises the following steps: consolidating the foundation by using a cement pile of which the diameter is 50 cm to 120 cm and the length is 3 m to 5m; and quickly constructing a gravel pile or a sand pile at the central position of the cement pile within 12 to 72 hours after the cement pile is formed and before the cement is completely solidified, wherein the diameter of the gravel pile or the sand pile is at least 10 cm smaller than the diameter of the cement pile; the gravel pile or the sand pile is 6 m to 25 m in length; and the gravel pile or the sand pile adopts soil-extrusion hole formation construction. According to the foundation treatment method provided by the invention, the cement is combined with the gravel pile or the sand pile in application, so the foundation treatment method achieves good environmental protection property, liquefaction resistance, high adaptability, convenience in construction, good economical efficiency and high foundation strength.

The invention relates to the field of foundation soil site category discrimination in geotechnical engineering investigation and building earthquake resistance, in particular to a liquefaction discrimination method and system combining static sounding and shear wave velocity testing, and the method comprises the following steps: creating an initial database; matching the shear wave velocity of the sandy soil by using the initial database so as to perfect the initial database to obtain a complete database; defining an interpretation variable according to the complete database, establishing an initial liquefaction probability model, and perfecting the initial liquefaction probability model by using the interpretation variable so as to obtain a liquefaction probability calculation formula; carrying out deformation solution on the liquefaction probability calculation formula to obtain a liquefaction resistance ratio formula; and obtaining a liquefaction judgment result of the sandy soil by utilizing the liquefaction resistance ratio formula and combining the liquefaction stress ratio. According to the method, static sounding and shear wave velocity testing are combined, the mechanical response of the soil body can be accurately and comprehensively reflected on the basis of the advantage complementation principle, and liquefaction judgment is accurately carried out.

The invention provides a gas on-line detection sampler. The sampler comprises a gas sample channel and a flow control part, and a gas sample heating and temperature control part. Thereinto, the gas sample channel comprises a sampling joint, a gas chamber, a flow regulating valve and an output switch valve; a heating chamber comprises an electrothermal core and a temperature relay which are disposed in the closed heating chamber, and a heating power line is led out in an isolating and explosion-proof manner. The sampler is directly mounted on an industrial apparatus, and is applicable to different interfaces only by changing the joint. In an operating temperature of about 60 DEG C, the sampler not only can ensure the stable output of the sample gas which is easy to be throttled and liquefied, but also can prevent air pollution and is explosion-proof, and can be directly mounted in sites with inflammable and explosive industrial gas. The sampler has various functions such as high pressure resistance, liquefaction resistance, explosion resistance, flow regulation, output switch, changeable inlet joint, low adsorption, easy purging, air pollution resistance and the like, and is widely applicable to the on-line sampling and transportation of various industrial gas below 25 MPa.

The invention discloses a liquefiable foundation device for micro-nano bubble processing and an operation method. In terms of a liquefiable sand layer in a foundation, a mixture of micro-nano bubbles and water is injected through a micro-nano gas-liquid mixture generator, a compressor, an air guide pipe, a hollow drilling pipe, a gas sprayer and the like, the micro-nano bubbles can stay in soil for a long time, the saturation is reduced, shearing strength of the soil is enhanced, and accordingly liquefaction resistance of the liquefiable sand layer is remarkably improved. When the liquefiable sand layer bears a vibration load, gas left in the soil can serve as a buffering agent and effectively buffer the tendency that pore water pressure rises, and accordingly the liquefaction resistance of the foundation is improved.

The invention belongs to the technical field of foundation treatment liquefaction resistance, and provides a visual clogging simulation system of a gravel pile drainage structure and a simulation method thereof.The visual clogging simulation system mainly comprises a gradation simulation device, the gradation simulation device comprises a device frame body and a model groove, the upper end of the model groove is open, and a plurality of containing cavities are formed in the model groove; one end of the model groove is provided with a water inlet, and the other end is provided with a water seepage port; the vertical stress loading device comprises an air bag and an air compressor, and the air bag is arranged at an opening in the upper end of the model groove; the seepage pressure loading device comprises a middle liquid storage tank, the output end of the middle liquid storage tank is communicated with the water inlet, and the input end of the middle liquid storage tank is respectively communicated with a water supply source and the air compressor. The invention further discloses a visual clogging simulation method. The method can be used for evaluating the reverse filtration effect of gradation of the gravel material and the change of the permeability coefficient in the long-term service process, and provides more accurate test reference data for the design of the drainage and liquefaction resistance effect of the gravel pile.

The invention provides a composite drainage structure suitable for liquefaction resistance of a high-fine-grain-content sand layer and a construction method thereof.The composite drainage structure suitable for liquefaction resistance of the high-fine-grain-content sand layer comprises a plurality of gravel piles arranged in a foundation needing to be treated and a gravel hardcore arranged on the surface of the foundation needing to be treated, and geotechnical drainage assemblies are arranged in the gravel piles; the top end of the geotechnical drainage assembly is inserted into the broken stone hardcore, the geotechnical drainage assembly comprises a drainage pipe and geotechnical cloth wrapping the outer side wall of the drainage pipe, and drainage holes are formed in the drainage pipe. The method is low in cost and good in durability, and the drainage capacity cannot be affected by sand layer particle clogging.

The invention discloses a device and a method for improving the soil resistance to liquefaction of submarine pipeline landing section interval.The devicefor improving the soil resistance to liquefaction of submarine pipeline landing section interval comprises a soil covering unit, a wave force dispersion unit and an auxiliary drainage unit, wherein the soil covering unit comprises a weighted base disposed in the trench and a temporary covering body arranged above the weighted base; the wave force dispersion unit includes a curved pad arranged in the trench backfill; the auxiliary drainage unit includes a drainage sleeve disposed on both sides of the soil weight unit and a backfill gravel arranged in the drainage sleeve. According to the device and the method for improving the soil resistance to liquefaction of submarine pipeline landing section interval, the soil is strengthened and compacted by increasing the heavy load of the soil;the auxiliary drainage unit is arranged, sand gap isreduced,and sand drainage ispromoted; and at the same time, the upper wave force dispersion unit is installed after the pipe is backfilled, and strives to further enhance the anti-liquefaction ability of the sand layer on the pipeline route of the submarine pipeline landing section, improves the stability of the soil in the landing section of the submarine pipeline, and ensures the operation safety of the pipeline.

The invention discloses an exploding and draining system used for processing a liquefied foundation. A liquefiable soil layer is located in the liquefied foundation, and the system is characterized by comprising multiple vertical draining plates distributed at intervals, multiple exploding holes distributed at intervals and explosive and concrete which fill the exploding holes from top to bottom, the draining plates penetrate the liquefiable soil layer, and the buried depth of the explosive is located within the liquefiable soil layer. The system has the advantages that vertical draining channels are provided, the dissipation of pore water pressure can be accelerated through the instantaneous impact force generated by the explosion, the moisture of the foundation can be discharged, and the purposes of fast settling and compacting and eliminating liquidation are achieved; the construction can be greatly accelerated, the construction period is shortened, and compared with the method for processing the liquefied foundation with a pile foundation, the system is low in cost, simple to operate and good in liquefaction resistance effect; the application range is wide, and the system is applicable to general liquefied foundations.

The invention relates to a liquefaction control method of blow filling sand based on straw degradation and microbial grouting and formed control structure. The control method is an environment-friendly method for controlling liquefaction of the blow filling sand and improving soil quality. According to the control method, water absorption characteristic of straw is used for reducing water contentof sandy soil, and saturation degree of the sandy soil is reduced through degradation and gas production characteristics of the straw. Meanwhile, the straw degradation and the microbial grouting promote each other. The sandy soil is reinforced by reducing the saturation degree of the sandy soil and improving mineralization of microorganisms, and finally liquefaction resistance of the blow fillingsand is improved.

The invention relates to a concrete drainage pile with an annular reinforced permeable sleeve and a pile forming method. The concrete drainage pile comprises a soft permeable pipe. A cast-in-place permeable concrete pile is arranged in the soft permeable pipe. A spiral spring steel ring is arranged outside the soft permeable pipe as a support. The concrete drainage pile with the annular reinforcedpermeable sleeve is used for liquefaction resistance and foundation consolidation drainage acceleration, the permeable concrete is used as a vertical drainage body, the soft permeable pipe is arranged outside to prevent the permeable concrete from being blocked, the process is simplified, and meanwhile, the spring steel ring on the soft permeable pipe can enhance the strength of the pile to a certain extent.