323 results about "Consolidation (soil)" patented technology

The invention discloses a soil one-dimensional consolidation, penetration, stressing relaxation combined test instrument and usage, which posits punch inside a punch cavity at the bottom of pressure container. It can do consolidation and compression to the same soil sample K0, it also can do soil sample penetration test and stressing relaxation test directly and simultaneously. It can test the soil sample's value of coefficient of static lateral pressure K0 and the process of pore water pressure followed by time. The test instrument and method can arrange soil's consolidation characteristic parameter by test outcome and using theoretical formula penetration method. It can do soil's theological behavior analysis by the outcome of stressing relaxation test.

An apparatus for measuring permeability accurately in expansive clay and non-expansive soils is provided. The apparatus includes hollow porous stone cylinders which prevent the sample from bulging and at the same time allow application of confining pressure on the soil sample enclosed in a flexible membrane, which simulates the field condition and allows for application of back pressure to aid in saturation. The apparatus also allows for accurate comparison of hydraulic characteristics of swelling clays with fluids of various dielectric and other properties. The apparatus can also be used to consolidate the sample either three dimensionally or in one direction and perform permeability tests as well as find out the consolidation characteristics of the sample.

Standard test methods for determining one-dimensional consolidation properties of soils using incremental loading in accordance with ASTM D2435, or AASHTO 216, and of those of other international and organizations, do not accurately predict the values of vertical settlement, coefficients of consolidation in horizontal and vertical directions, and modulus of elasticity in vertical direction, because fixed ring used in these tests do not allow horizontal settlement and dissipation of excess pore-water pressures in horizontal direction, whereas, in field, under application of a vertical load, both horizontal and vertical settlements occur along with dissipation of excess pore-water pressures in both vertical and horizontal directions. To overcome this more than 100 year old problem, the inventor (Dr. Ramesh Chandra Gupta, Ph. D., P.E.) has invented a test device for determining three-dimensional consolidation properties of soils, using a flexible ring which permits development of horizontal and vertical displacements, and dissipation of excess pore-water pressures in both horizontal and vertical directions, along with increased lateral resistance as takes place in field at any depth in a soil deposit when vertical load at the surface is applied.The flexible ring consists of filter fabric around the soil specimen, rubber membrane around the filter fabric, circular segmental metal plates around the membrane and elastomeric rubber bands or spring loaded jacket around the segmental plates, and allows horizontal and vertical displacements, dissipation of pore-water pressures in horizontal and vertical directions to take place with increased lateral resistance with each increment of vertical load like those in the field. Thus new test device simulates field condition to allow accurate determination of three-dimensional consolidation properties of soils (such as settlements, coefficients of consolidation in horizontal and vertical directions, and modulus of elasticity).For this new test device, conventional incremental consolidation frame or triaxial type chamber system either with the triaxial loading system or modified to adapt to incremental consolidation frame, shall be used to perform three-dimensional consolidation tests.

The invention relates to a hydraulic model with the international patent classification (IPC) of E02B 1 / 02, in particular to a high sediment concentration waterflood river bed tearing simulation test method. The method utilizes a special test device and adopts flyash as model sand, wherein extremely fine flyash with a median diameter being smaller than 0.01mm is adopted to simulate an adhesive mud layer of deposits, fine flyash with a median diameter of 0.03mm is adopted to simulate suspended sand, and coarse particle flyash with a median diameter of 0.05mm is adopted to simulate loose bed sand. The invention provides a feasible test method for researching the problems of a river bed tearing phenomenon of the Huang river and the breaking of consolidation cohesive soil of the water conservancy industry, lays foundations for recognizing the generation mechanism of the river bed tearing phenomenon and establishing a scouring index of river bed tearing, and plays a certain active role in the development of the subject of river sediments.

The invention relates to a high-performance sand-soil consolidation material, as well as a preparation method and a using method thereof. The high-performance sand-soil consolidation material belongs to a mortar composition and is characterized by comprising the following raw materials in parts by weight: 5-40 parts of cement clinker, 3-6 parts of gypsum, 4-10 parts of alkali additive, 0.5-6 parts of compound activating agent, 1-4 parts of early strength agent, 2-10 parts of mineral activating agent, 3-8 parts of expansion agent and 22-77 parts of micro-powder formed by fine grinding of blast furnace water-quenched slag. The invention provides the high-performance sand-soil consolidation material which has the advantages of simple operation, convenient construction, good water resistance, fast consolidation, high early strength, stable improvement of post-strength, resistance to erosion of underground inorganic salt water, excellent anti-seepage performance and low production cost, as well as the preparation method and the using method thereof. The high-performance sand-soil consolidation material is suitable for consolidating mine tailings, natural weathered sand, fly ash, gravel, stone chips, stone powder, soil, sludge, construction waste, coal gangue and phosphorus slag into a solid material, and can be used for laying a subgrade, constructing a wall body and constructing a site foundation.

The invention provides a reinforcing device for reinforcing a sand foundation through combination of microorganisms with vacuum drainage and a reinforcing method of the reinforcing device. The device comprises grouting pipes, drainage pipes, a grouting well array, a drainage well array, vacuum water pumping equipment and slurry grouting equipment, wherein the grouting pipes and the drainage pipes are laid on a sand surface in parallel in the horizontal direction, the grouting well array and the drainage well array are located in the sand foundation below the grouting pipes and the drainage pipes respectively, the grouting well array comprises at least two grouting wells, and the drainage well array comprises at least two drainage wells. The reinforcing method comprises steps as follows: I, the reinforcing device is mounted; II, a bacterial solution and a consolidation fluid are prepared; III, the bacterial solution is injected; IV, vacuum drainage is preformed; V, the consolidation fluid is injected; the steps IV and V are repeated for 6-7 times. According to the reinforcing device and the reinforcing method, directional horizontal migration of the microorganisms in a soil body is realized through vacuum drainage, and the treatment range is enlarged; plug holes produced in the grouting process are reduced, and the reinforcement uniformity is improved.

The invention discloses a construction method for a collapsible loess foundation. The construction method comprises the following steps of: firstly, performing foundation treatment on a loess field with collapsibility by using a super downhole dynamic consolidation (SDDC) pile; secondly, collecting undisturbed soil on site, normally performing an indoor experiment to measure an inter-pile soil compaction coefficient and an SDDC pile body compaction coefficient, evaluating the collapsibility, and if any one of the three indexes cannot meet a design requirement, performing pile compensation construction on the SDDC pile until the design requirement is met; and finally, pouring the pile and mudjacking. The method has the advantages of economy, environment friendliness, high treatment depth, good treatment effect, large bearing potential, high complicated load resistance and the like. By application of the method, various side effects caused by the collapsibility of the deep collapsible loess field can be eliminated, and requirements of upper-part high rise buildings on the bearing capability and settlement of the foundation can be met.

The invention relates to a compound reinforcing method capable of rapidly falling-silt, promoting-seepage, prepressing, reinforcing and blow filling soft clay. The method comprises the following steps: mixing water and soil separating agent and sucking silt mud, introducing the mud mixed with the water and soil separating agent into a cofferdam for silt falling, appearing obvious and rapid solid-liquid separation of the mud in the cofferdam, and overflowing and discharging or recycling the separated tail water containing extremely few of solid matters from the far end of the cofferdam; after filling, silt falling and discharging, respectively inserting a plastic drainage plate, laying a plastic drainage pipe, geotextile and a plastic film on the surface layer of the silt, utilizing a vacuum pump to suck to form negative pressure at the lower part of the plastic film, discharging water in silt body on the surface layer by means of atmosphere pressure to lead the bearing capacity of siltbody on the surface layer to be improved rapidly, establishing an operation platform for follow-up soft base treatment, such as vacuum preloading, pile deep stirring, electroosmosis and plate body stabilizing and other technologies, thus realizing the filling-silt overall soft foundation consolidation treatment purpose in the cofferdam. The technology of the invention reduces the construction time of filling soft soil foundation to half and the cost to a half, is popularized and applied, and has extremely economic and social benefits.

The invention discloses a method for monitoring the expansion and shrinkage deformation of a deep soil body under the influence a hot and rainy climate. The method comprises the following steps: A. sample making and sample loading: spreading a silt layer or permeable stones at the bottom of a model groove, performing air drying on the soil sample, smashing, sieving and measuring the water content rate and density, loading the prepared soil samples in a spreading manner in layers, and sealing and standing the model groove to obtain consolidation settlement; B. wetting-drying circular test: leaching the soil samples by utilizing distilled water through a watering pot, and baking the soil samples by utilizing a reflection-type heater; C. data collection: recording each dial gauge reading, the water content rate in the soil body and the temperature in the soil body and the indoor temperature in drying and wetting process; and D. data processing: recording the numeral value of each dial gauge as an initial value of the deformation before the humidification process is implemented, and subtracting the initial value from the recorded dial gauge reading as the deformation value of the soil sample. By utilizing the method provided by the invention, the influence of the external environment on the experimental result is lowered and the reliability of the monitoring result is improved; and the method is simple in operation.

The invention relates to a filing-free vibroflotation method, characterized in setting the following vibroflotation parameters: a. setting the vibroflotation depth to more than differences between the hydraulic sand-filling level and the ground level, and less than differences between the hydraulic sand-filling level and the undisturbed soil level; b. setting the vibroflotation space to 2m-3m, and the vibroflotation hole site is arranged as an equiangular triangle; c. setting the vibroflotation dense current to 20A-25A; d. setting the vibroflotation time to 8s-10s in hole center, and 30s in hole bottom; e. setting the hydraulic pressure to 0KPa-50KPa when vibroflotation; f. setting the vibroflotation descent rate to 0m / min-2m / min, and the lifting rate to 1m / min-2m / min; g. setting the vibroflotation mode to double or triple. Processing powdered sand bed foundation by said method is simple, saves construction costs and has good consolidation effect.

The invention discloses a slurry consolidating apparatus and a use method thereof. The slurry consolidating apparatus comprises a power supply system, a sample production platform system and a die system. The method comprises the following steps: mixing fine grained soil with air-free water, pouring the obtained mixture into a container, sealing, storing, and stirring after water is fully absorbed; completing assembling of the die system; fixing the die system to a sample disposing base plate of the sample production platform; pouring a slurry into a sample die through a funnel; adjusting the height of a reaction force crossbeam to make a presser contact with the upper surface of the slurry; starting an inflator, and carrying out grading loading; allowing the sample to be in a sealed state; and applying an axial consolidating pressure, and respectively adding negative pressures with equal size to a top cover and a die pedestal to accelerate consolidation until consolidation is completed. The apparatus and the method effectively reduce the disturbance possibility of the sample, improve the repeatability of the sample, make the sample have uniform water content and particle size distribution, and effectively improve the sample production efficiency and the quality of the sample.

The invention provides a stability analysis method for hydromechanical coupling of an unsaturated soil slope, and belongs to the technical field of rock and soil. According to the stability analysis method, a Barcelona basic model more conforming to the property of the unsaturated soil is adopted for a constitutive model of the unsaturated soil, and the influence of suction force and the influenceof shear strength and compressive strength of a soil body are considered in the constitutive model. According to the strength reduction method for unsaturated soil slope stability analysis, the shearstrength of a soil body is reduced by reducing the cohesive force and the friction angle of the soil body. In addition, the reduction of the compressive strength of the soil body is taken into account by reducing the consolidation pressure in front of the soil body. The stability analysis of the unsaturated soil slope is carried out under the Cosserat continuum frame, and the influence of the microstructure effect of the soil body on the stability of the macroscopic slope is considered to a certain extent. According to the stability analysis method, various influence factors are considered, and the stability analysis accuracy of the unsaturated soil slope is improved.

The invention belongs to testing equipment in the field of geotechnical engineering, and particularly relates to a device for testing consolidation and permeation of soil under the action of coupling of chemistry and stress. A pressurizing frame (3) is arranged on the left side of the top of a table plate (4); the lower end of the pressurizing frame (3) is connected with a lever penetrating sleeve (3-1); a lever support (4-1) is fixed under the left end of the table plate (4); a lever (5) penetrates through the lever support (4-1) and the lever penetrating sleeve (3-1); a balance weight (8) is arranged at the left end of the lever (5); a weight tray (6) is arranged below the right end of the lever (5); a weight (7) is arranged on the weight tray (6); a permeation and consolidation container base (9) with a groove is arranged in the pressurizing frame (3) on the table plate (4); an exhaust hole (9-4) and a water draining hole (9-6) are formed in a pressurizing piston (9-5); the pressurizing piston (9-5) is provided with an arc-shaped pressing block positioning groove (9-11); and the arc-shaped pressing block positioning groove (9-11) is connected with a pressing block (17). The device is simple in structure and convenient to operate, and has excellent corrosion resistance and tightness.

The invention discloses a prefabricated tubular pile capable of draining water and increasing frictional resistance and a construction method thereof. Small holes are formed in the side surface of the prefabricated tubular pile and are distributed in a staggered mode randomly. Geofabric is arranged on the prefabricated tubular pile in a sleeving mode, and the prefabricated tubular pile is implanted into soil. After water in soil around the pile permeates into an inner pipe through the geofabric via the small holes distributed in the side surface of the prefabricated tubular pile, water draining is carried out. After drainage consolidation, the geofabric is punctured, and the soil around the pile enters the inner pipe through the small holes in the side surface of the prefabricated tubular pile. The soil around the pile is continuously poured into the inner pipe from the top of the prefabricated tubular pile, after leveling, broken stone hardcore and grid backfill is carried out, and after backfill, the height of a top layer grid is the same as designed elevation. Low-pressure pile force construction can be used for obtaining a high-bearing-capacity pile, the purposes that pile foundation bearing force and construction efficiency are effectively improved are achieved, the side frictional resistance of the pile is improved, noise and mud pollution are avoided during construction, disturbance on the ground is low, the structure is simple, construction speed is high, the cycle is short, and efficient and quick results can be achieved in emergency engineering.

The invention discloses a method for analyzing the development and change rule of the negative frictional resistance of an ultra-long pile foundation under the action of heaped loads. The method aimsat the condition of large-area stacking; the problem that a building is damaged due to negative frictional resistance caused by pile-soil settlement difference of an ultra-long pile foundation is studied. The calculation method comprises the following steps that by analyzing pile side soil body three-dimensional consolidation settlement, pile body compression deformation and pile end soil body settlement, a load transfer model considering side resistance softening is introduced, and according to the pile body displacement balance principle and based on a matrix transfer method, a super-long pile negative friction analysis model under the pile loading effect is established. Engineering examples are analyzed through a theoretical model and a numerical simulation method, meanwhile, comparisonverification is conducted on the engineering examples and corresponding actual measurement data, the development and change rule of the negative friction resistance of the super-long pile foundationunder the pile loading effect is obtained, and a theoretical basis is provided for super-long pile foundation bearing capacity design.

The invention discloses an electroosmosis united air pressure separation device and technology. In the device, an anode is connected to an externally connected air pressure source on the basis of an electroosmosis device, and fumaroles are drilled within 1 / 2 of the bottom of the anode; the anode serves as a gas ejector pipe; a part of a cathode which enters into a to-be-processed soft clay part is provided with drain holes, and the cathode serves as a drain pipe. The electrodes of the device are distributed in the way of parallel staggered distribution. The technology comprises the steps of: spraying gas to the flexible clay through the anode 12-30 hours after the electroosmosis is performed, controlling the air pressure within 250 kPa to 400 kPa for 10-20 min, then spraying high-pressure gas every four times. According to the invention, the beneficial effects below are achieved: 1) the drainage amount and the soil anti-shearing intensity of the electroosmosis united air pressure separation technology is increased by 10-16% than a pure electroosmosis technology when the soft clay in the same batch and with the same volume are processed for the same time, and 2) the electroosmosis united air pressure separation technology is better to be conductive to the drainage consolidation of deep soil than the pure electroosmosis technology.

Disclosed is a horizontal drainage consolidation method through blow filling of soft soil. The horizontal drainage consolidation method includes that (1), in a blow filling area, zoning is performed according to width of 50-125m to form a plurality of zoning areas; (2), on two sides of the zoning areas, a plurality of longitudinally-arranged vertical pipes are arranged on a vertical plane, and the bottom ends of the vertical pipes on the two sides are communicated with longitudinal horizontal pipes respectively; (3), a plurality of flexible transverse drainage plates are arranged horizontally, and two ends of the flexible transverse drainage plates are communicated with longitudinal horizontal pipes on two sides respectively; (4), performing blow filling of the soft soil in the zoning areas to form a first layer; (5), longitudinal horizontal pipes are arranged on the first layer, after being subjected to blow filling of the soft soil, in each zoning area along the sideline of the zoning area, middle areas of the vertical pipes on the two sides are communicated with longitudinal horizontal pipes respectively, a plurality of flexible transverse drainage plates are horizontally arranged, two ends of the transverse drainage plates are communicated with the longitudinal horizontal pipes on the two sides respectively to form a second layer, and the transverse drainage plates among layers are parallel to one another; step (4) and step (5) are repeated and so on to form a plurality of layers; the layers are communicated with one another, and vacuumizing equipment is communicated with the vertical pipes for vacuumizing.

The invention discloses a device for rapidly and uniformly preparing triaxial test soil samples and method thereof. The device comprises a consolidation forming cylinder, a consolidation forming cylinder upper cover plate, a consolidation forming cylinder base, a piston rod, a piston plate, rigid screws, bolts, and a drainage tube, and also is provided with a silica gel air bag, a pneumatic threaded joint, a positioner, and an air tube. The consolidation forming cylinder is made of microporous steel wire mesh, so that water can be drained.; Drainage holes are arranged on the consolidation forming cylinder base. Drainage holes are formed in the piston plate and the piston rod, so that water can be drained up and down and can be drained around the periphery when the soil sample is prepared.The positioner is arranged on the piston rod to control the prepared soil sample height, so that the prepared soil sample density is controlled. The silica gel air bag is placed in the consolidation cylinder, connected with the pneumatic threaded joint on the upper cover plate, and the silica gel air bag is expanded and compressed by an air compressor to compress the soil sample downwards, the pressure is constant, and the sample is uniform. According to the device for rapidly and uniformly preparing triaxial test soil samples and method thereof, the device is applicable to all kinds of soil,triaxial test soil samples can be prepared uniformly and rapidly, and the prepared soil sample can be applied to triaxial compression and shearing tests.

A construction method for a shallow-buried multi-arch tunnel under water-rich geological conditions includes the following steps: cleaning a grouting ground surface; marking a grouting reinforcement scope; performing survey setting-out; drawing a cross-section diagram to scale; calculating out coordinates and angles of anchor points that need to be set; marking drilling positions; nailing small wooden piles at the drilling positions for identifying; determining a setting depth of the anchor rods according to ground elevation; drilling holes, cleaning bottom of hole, grouting, performing construction preparation, performing long pipe shed construction at the entrance after an earth-rock of a tunnel entrance and an open cut tunnel is excavated to flush with a springing line of the tunnel. A down-the-hole drill is used for drilling in construction. Long pipe shed grouting is designed based on solidifying a soil mass in limited scope around a consolidation pipe shed.

The invention discloses a seabed soft-soil layer preparation device and method for a large-dimension physical model test, and belongs to the technical field of geotechnical engineering tests. The seabed soft-soil layer preparation device comprises a consolidation and sample preparation system, a monitoring and control system, and a counter-force loading system, wherein the consolidation and samplepreparation system is pressurized from the upper part under a certain water-head condition, and consolidates a soil sample under a double-sided water draining condition, and density of the soil sample is tested; the monitoring and control system can monitor state changes of the soil sample in real time through sensors arranged in a soil sample consolidation region and an upper loading region, sothat various physical and mechanical parameters, such as moisture content, soil pressure, pore water pressure and a pore space ratio, of the soil sample are obtained; and the counter-force loading system can apply stable and uniform consolidation pressure to the soil sample consolidation region, and can reduce and even eliminate influences of unsymmetrical pressure. Three systems cooperatively work, so that real-time feedback is realized, and sample preparation ends while needed sample preparation standards are reached. The device is strong in applicability, is easy in connection, is simple and convenient in operation, is good in sample preparation integrity, is uniform and consistent, and is also suitable for seabed soft soil and ultra-soft soil sample preparation.

The invention relates to the technical filed of building foundation treatment, and discloses a method for treating miscellaneous fill foundation combing dynamic consolidation and compaction grouting. The method includes the following steps that firstly, construction of the dynamic consolidation is conducted; secondly, after the dynamic consolidation is completed, hole clearances or holes inside a soil body are detected, and therefore a grouting range is determined; thirdly, the grouting is designed; fourthly, the compaction grouting is conducted. By means of the method, comprehensive reinforcement treatment is conducted on the miscellaneous fill foundation, the advantages of the methods of the dynamic consolidation and the compaction grouting can be taken fully, the hole clearances or holes inside the soil body can be effectively treated, the bearing capacity and overall stability of the foundation can be improved, and therefore the problem that differential settlement of the miscellaneous fill foundation is prone to generating is overcome; in addition, compared with other methods for treating miscellaneous fill soil, the cost is low, the technology is simple and convenient, the implementation effect is good, construction waste can be recycled, and finally the purposes that land resources are saved, and the ecological environment is protected are achieved.

The invention discloses a negative skin friction (NSF) removing foundation treatment method. A method for combining discrete piles and flexible piles is used for treating NSF caused by self-weight consolidation of a soil body, gravel piles or sand-gravel piles can serve as the discrete piles, the discrete piles and the flexible piles are arranged at intervals, and gravelly soil cushions are laid on the foundation surface above the discrete piles and the flexible piles. According to the NSF removing foundation treatment method, self consolidation settlement of foundation soil is reduced by construction compaction and vibro-compaction of the discrete piles, loads can be transmitted to foundation supporting layers by the construction of the flexible piles so that stress and compressive deformation of a reinforced zone can be reduced, and 'extrusion' and 'clamping' effects can be achieved on soil among piles under the combined action of the discrete piles and the flexible piles so that consolidation settlement of the foundation soil and NSF caused by the consolidation settlement of the foundation soil can be inhibited. Meanwhile, the combined foundation treatment method can improve bearing capacity of a foundation to a large extent by drainage consolidation and substitution of the flexible piles.

The present invention discloses a foundation treatment method for exactly regulating foundation settlement, and a construction device, and belongs to the technical field of civil engineering. According to the method, the number of squeezing expanding apparatuses and the amount of diameter expansion are determined according to settlement prediction of the foundation to be eliminated; with gradual expansions of the squeezing and expanding apparatuses in the soil according to the specified rates, horizontal loads are applied on the surrounding soil, such that the soil is forced to be subjected to drainage consolidation, the porosity is reduced until the pore reduction meet the design target value so as to realize a purpose of exact regulation of the foundation settlement. The construction device is the squeezing and expanding apparatus. The squeezing and expanding apparatus comprises at least an II type squeezing and expanding apparatus unit, which can form an oblique extension type diameter-variable pile pore after expanding. According to the present invention, with diameter-variable squeezing and expanding, according to the preset target, the pores in the foundation are exactly andquantitatively eliminated so as to achieve the purpose of exact regulation of the foundation settlement prediction; for the road widening project, the settlement difference between the old road foundation and the new road foundation can be exactly controlled; the construction device is convenient, the construction method is simple and the cost is low.

A clogging preventing method for drainage channel based on an underground high-flow-capacity drainage system comprises connecting the upper opening of a high-flow-capacity drainage body with a flexible water permeable pipe, and pressing into to-be-treated super-soft soil until reaching a design depth or hard shell course while reserving a section of the flexible water permeable pipe above the ground; connecting the flexible water permeable pipe with a drainage branch pipe, connecting the drainage branch pipe in a centralized way to a drainage main pipe, connecting the drainage main pipe to the water inlet of a sediment box and connecting the water outlet of the sediment box to another section of drainage main pipe and further to a pump and a drainage pipe; arranging a seal film and pressing a groove in the region where the drainage body is arranged; starting up the pump for evacuation; and choosing the time for stopping evacuation according to the super-soft soil surface settlement rate and predicted treatment effects. The invention can satisfy the requirement for construction period and strength uniformity of soil mass after drainage consolidation treatment, and realizes clogging preventing and treatment based on fine particle dredging.

The invention discloses a device for accelerating consolidation of soft soil through a combination of a frost heaving and melting shrinking method and vacuum preloading. The device comprises freeze pipes and plastic drain boards. The freeze pipes and the plastic drain boards are distributed and buried in the soft soil to be subjected to drainage and consolidation in a lattice mode. The freeze pipes and the plastic drain boards are distributed in a staggered mode. The plastic drain boards are communicated with a water collecting tank through vacuum jet pumps. One ends of the freeze pipes are communicated with a brine circulating tank. The other ends of the freeze pipes are communicated with the brine circulating tank through a brine pump. The brine circulating tank is connected with a brine cooling device. The invention further discloses a method for accelerating consolidation of the soft soil through the combination of the frost heaving and melting shrinking method and vacuum preloading. A fine-particle soft soil body has an obvious frost heaving phenomenon when freezing, so that a vacuum pressure field is effectively superimposed on a frost heaving compaction pressure field, and accordingly the discharge rate of water can be increased by several times.

The invention provides a method for carrying out dynamic compaction composite treatment on a sludge soil foundation through gravel piles, a drain board and an upper filling body, and belongs to the technical field of building foundation treatment. The method comprises the steps that S1, a construction cushion layer is laid; S2, construction of the gravel piles is achieved, and a vibration sunken tube method is adopted; S3, geotechnical cloth and a cushion layer below the tops of the gravel piles are laid; S4, construction of the plastic drain board is achieved; S5, an upper cushion layer and geotechnical cloth are laid; and S6, layered and staged dynamic compaction of the filling body is achieved. By means of the method, the advantages of preloading and dynamic compaction dynamic consolidation of the gravel piles and the plastic drain board are achieved fully, the advantages are complemented, and the defects of a single foundation treatment method are avoided.

The invention discloses a deep soft foundation consolidation settlement layering summation algorithm based on soft soil parameter spatial anisotropy. The algorithm comprises the steps: carrying out the layering and partitioning of a soft soil foundation according to the stratum condition of a soft soil region; calculating the vertical self-weight stress of the foundation at the layering position;calculating foundation additional stress, and obtaining foundation additional stress at each layered interface; if the thickness of the subarea is relatively large, dividing the area into layers according to intervals; averaging and calculating the average value of the self-weight stress and the additional stress of each layered foundation according to the stress of the upper bottom surface and the lower bottom surface of each layer, determining the depth of a foundation compression layer, determining a subarea where a soil layer is located, calculating the main consolidation settlement amountof the soft soil foundation of each layer, calculating the total main consolidation settlement amount, and calculating the total final settlement amount; calculating the foundation consolidation degree at any moment; and predicting the foundation settlement amount. According to the deep soft foundation consolidation settlement layering summation algorithm, the property change of the deep soft soil at different depths is considered, the deep soft soil foundation settlement prediction precision is improved, and post-construction settlement prediction and control of engineering construction in adeep soft soil area are realized.

The invention belongs to the related technical field of treatment of sludge slurry with ultrahigh water content. The full-automatic hydraulic permeation consolidation device comprises a water pressurecontrol assembly, a permeation consolidation assembly, a measuring assembly and a data acquisition assembly, the water pressure control assembly is connected with the permeation consolidation assembly, and the measuring assembly is arranged on the permeation consolidation assembly and connected with the data acquisition assembly; the consolidation device is used for realizing drainage consolidation of a soil body through pushing and friction dragging effects of seepage force of high-pressure water on a soil sample; the water pressure control assembly is used for controlling the seepage force,and the data acquisition assembly is used for acquiring the pore pressure at each depth of a soil sample in the seepage consolidation assembly, the displacement at each time and the drainage rate inreal time so as to obtain the seepage coefficients of different stages. According to the invention, the filter pressing benefit is improved, real-time and automatic acquisition of test data is realized, large errors caused by manual reading are avoided, and the test data is accurate and reliable.

The invention discloses a triaxial consolidation test-based method for confirming a relationship between a soil body permeability coefficient and a void ratio. The method comprises the following steps: firstly, acquiring a test soil sample, and acquiring an initial void ratio e0 of the soil sample by tests; secondly, preparing a test sample, and carrying out saturation treatment on the prepared test sample; then, carrying out a classification pressure-reduction seepage triaxial consolidation test on the test sample, and recording the pore pressure value and the volume variation value of the test sample in the testing process; then, treating recorded testing data, and calculating the permeability coefficient and the void ratio in the classification pressure-reduction process; and finally, confirming the relationship between the soil body permeability coefficient and the void ratio. According to the invention, a triaxial consolidometer is adopted for carrying out classification pressure-reduction seepage testing on the soil body test sample, and the permeability coefficient and the void ratio in a classification pressure-reduction test each time are calculated according to the pore pressure value and the volume variation value in the testing process, and finally the relationship between the soil body permeability coefficient and the void ratio is confirmed. The method is simple in principle, is convenient to operate, is accurate and reliable, and can rapidly determine the variation rule of the permeability coefficient.

The invention relates to the field of foundation treatment researches, and aims at providing a vacuum preloading and piling preloading combined settling column tester and a test method thereof. A partition steel plate is arranged in a settling column, and is connected with a displacement sensor through a hollow rigid sleeve, a water drainage plate is sleeved in the rigid sleeve, and the lower part of the water drainage plate is landfilled in a soil sample. The top of the settling column is provided with a cover plate, and a water bag is arranged in a space between the cover plate and the partition steel plate; the sidewall of the settling column and the rigid sleeve are respectively provided with vacuum tubes, and the vacuum tubes are connected to a vacuum pump; the bottom and the sidewall of the settling column are provided with a plurality of pore pressure sensors; and the pore pressure sensors and the displacement sensor are connected to a data acquisition system through signal lines. The tester and the test method have the advantages of simple structure, easiness in use, simplicity and convenience in changing of the piling load value through hydraulic control, effectiveness in obtaining the change of the pore pressure in different radial positions during consolidation, automatic data recording, reduction of manpower needed by experiments, reduction of errors caused by manpower reading, and realization of repeated sue and no wastes or pollution of a model materials and filled soil.