42 results about "Liquefaction resistance" patented technology

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 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 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 discloses a method for preventing earthquake liquefaction instability of an ultrafine tailing heaping upstream method tailing dam. An initial dam (5) and a dam abutment flood stop ditch (1) are built according to a design scheme; embedment depths of a first earthquake liquefaction resisting medium-coarse sand drainage/seepage layer and a second earthquake liquefaction resisting medium-coarse sand drainage/seepage layer are determined according to the region seismic fortification intensity; the first and second earthquake liquefaction resisting medium-coarse sand drainage/seepage layers both consist of medium-coarse sand drainage/seepage layers (11), and a row of groove hole drainage/seepage pipes (3) paved in the medium-coarse sand drainage/seepage layers (11); the groove hole drainage/seepage pipes (3) are communicated with drainage communicating pipes (2) through three-way pipes (12); and the outer ends of the drainage communicating pipes (2) are connected with the dam abutment flood stop ditch (1). The method improves the earthquake liquefaction resistance and the stability of the ultrafine tailing heaping dam, prevents the earthquake liquefaction instability damage, and in particular, is suitable for the ultrafine tailing heaping upstream method tailing dam in high-intensity earthquake region.

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 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 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.