35 results about "Maximum dry density" patented technology

The invention relates to the field of geotechnical engineering, and discloses a portable intelligent measuring device and method for the optimal moisture content and the maximum dry density of a soil mass, and the device comprises an automatic sample preparation system integrating stirring, heating and water adding functions, a similar compaction system based on static pressure and frictional resistance measurement, and an intelligent control system, the detachable inner barrel is used as a connecting core; the method comprises the following steps: automatically preparing a series of to-be-detected soil samples with different water contents, performing class compaction on each soil sample to measure corresponding interface friction resistance, and finally calling a conversion model by an intelligent system, and calculating and outputting the optimal water content and the maximum dry density. According to the invention, automatic sample preparation, indirect measurement and intelligent analysis are modularly integrated, so that a traditional compaction test is converted into an automatic test process which can be quickly and accurately completed on an engineering site, and the problems that the test period is long, the test depends on a laboratory, and site construction cannot be timely guided in the prior art are solved.

The invention belongs to the technical field of road engineering, and particularly relates to a roadbed solid waste modified soil tensile strength estimation method considering freeze-thaw cycle, which comprises the following steps: determining the maximum dry density and optimal water content of solid waste under different W / C conditions through a heavy compaction test; the method comprises the following steps: preparing a sample, and putting the sample into a high-low temperature alternating testing machine for freezing and thawing cycle treatment; then carrying out a tensile test; and finally, comparing and analyzing the tensile strength corresponding to the solid waste under different working conditions, and establishing a tensile strength estimation model comprehensively considering the solid waste clay ratio, the relative compactness, the saturation degree and the freezing and thawing cycle number. By comprehensively considering the influence of factors such as gradation variables, compactness variables, humidity variables and environment variables on the tensile strength, rapid prediction of the tensile strength of the solid waste material under different conditions is realized, the model is clear in physical significance and simple in structure, the test difficulty is reduced, obvious engineering convenience is provided for units without test conditions, and the test efficiency is improved. High market popularization values are realized.

The invention provides a same-measuring-point rockfill material grading upper envelope line prediction method and device, electronic equipment and a storage medium, and relates to the technical field of engineering geophysical exploration, and the method can realize the nondestructive detection of the initial quality of each particle group in a same-measuring-point rockfill material by using a surface image and a ground penetrating radar profile map in combination with a standard radar map. And the grading upper envelope line is calculated by adopting the maximum dry density, so that the obtained grading upper envelope line is closer to the real crushing and grading evolution state of the rockfill material. Moreover, the method adopts a nondestructive testing mode to predict the grading upper envelope line of the rockfill material at the same measuring point, the amount of data required to be detected is small, the calculation model is clear, the prediction efficiency can be improved, the prediction cost can be reduced, the influence on the construction progress of the dam can be avoided, the interference on the grading upper envelope line caused by introduction of human factors can be avoided, and the prediction accuracy is improved. And the accuracy of the grading upper envelope line is improved.

The invention discloses an internal tamping carrier pile backfill soil quality monitoring system and method, and belongs to the technical field of soil mass quality monitoring, the system comprises a monitoring assembly which comprises a plurality of sensor assemblies and is used for collecting pressure data and actually measured moisture content of backfill soil at different depths of an internal tamping carrier pile in the tamping process; the data transmission module is used for amplifying the data acquired by the sensor assembly and transmitting the data to the data processing unit; the data processing unit is used for converting the pressure data into equivalent additional stress and converting the equivalent additional stress into a void ratio; calculating the dry density of the backfill based on the void ratio and the actually measured water content; and finally, calculating the compaction coefficient of the backfill soil by adopting the dry density and the maximum dry density of the tamping foundation experiment. And the evaluation and decision-making unit is used for receiving the compaction coefficient calculated by the data processing unit, determining whether the compacted backfill soil on the layer where the sensor assembly is located is qualified or not according to the compaction coefficient, and giving a construction suggestion when the backfill soil is unqualified.

The utility model belongs to the technical field of engineering experiment equipment, and relates to an indoor maximum dry density test mold for aeolian sand roadbed water sinking method construction, which consists of a base (1), a bottom plate (2), a test cylinder (3), a sleeve (4), a fixing frame (5) and a fastening bolt (6), and is characterized in that the test cylinder (3) and the bottom plate (2) are sleeved on the base (1), the sleeve (4) is sleeved on the test cylinder (3), and the fixing frame (5) is sleeved on the bottom plate (2). The fixing frame (5) is connected with the base (1), and the fastening bolt (6) is used for fixing the sleeve (4) and the test barrel (6) on the base (1). The mold for the indoor maximum dry density test of the aeolian sand roadbed constructed by the water precipitation method is simple to operate, water can be smoothly discharged out of a test piece in the compaction process of the indoor maximum dry density test of the aeolian sand roadbed constructed by the water precipitation method, the maximum dry density of aeolian sand is favorably improved, and the compaction degree is improved.

The application discloses a kind of building solid waste-red clay mixed roadbed filler permanent deformation estimation model and modeling, estimation method, the maximum dry density, optimum moisture content and CBR value of building solid waste-red clay mixed roadbed filler under different building solid waste incorporation rate are determined by compaction test, California bearing ratio test;Prepare the building solid waste-red clay sample of different building solid waste incorporation rate, carry out dry-wet cycle test to it, carry out triaxial test to the sample after preset dry-wet cycle number, determine its resilience modulus and permanent deformation;Establish the elastic deformation increment estimation model considering building solid waste incorporation rate, dry-wet cycle number comprehensively, and then obtain the permanent deformation estimation model considering stress-strain relationship, physical state, cycle loading number, building solid waste incorporation rate, dry-wet cycle number comprehensively, then the permanent deformation of building solid waste-red clay mixed roadbed filler is accurately and quickly estimated using the permanent deformation estimation model.

The application discloses a method for treating and utilizing large-particle waste sand in ammonia-alkali method alkali waste liquid, and the process is as follows: treating the large-particle waste sand, reducing the content of soluble salt in the waste sand through water washing, controlling the content of soluble salt in the waste sand to be less than or equal to 2%, designing the mixing proportion of the waste sand lime cement soil, replacing the soil in the cement lime soil with different amounts of waste sand, keeping the mass ratio of the admixture lime and cement unchanged in each test, and decreasing the content of the soil corresponding to the waste sand proportion gradient; carrying out the compaction test on the materials in each group under different target moisture contents, obtaining the maximum dry density and the optimum moisture content of the sample; determining the waste sand replacement interval of the waste sand lime cement soil meeting the strength and the optimum proportion of the waste sand lime cement soil material; and preparing the waste sand lime cement soil for paving the roadbed or the base of the road. The application solves the phenomenon of pipe grinding in the process of filling the well with the alkali waste liquid, prepares the road material according to the designed proportion of the large-particle waste sand and the lime soil, reduces the cost of the alkali waste liquid, and changes the large-particle waste sand into the road raw material.

The application relates to the technical field of fertilizer groove backfilling, and particularly discloses a fertilizer groove backfilling construction method based on MICP technology. The fertilizer groove backfilling construction method based on MICP technology comprises the following steps: soil property determination: determining the maximum dry density p dmax of the soil, the optimal water content w, preparing a microbial slurry and a cementing solution, preparing backfill soil by adding the cementing solution into the soil, backfill construction: backfilling the fertilizer groove with the backfill soil by 300-400 mm, then spraying the microbial slurry on the surface of the backfill soil, continuing to backfill the fertilizer groove and spraying the microbial slurry after the microbial slurry penetrates to the bottom of the backfill soil, and repeating the above operation until the fertilizer groove is backfilled completely. The fertilizer groove backfilling construction method based on MICP technology has the advantages of low construction cost, simple construction method and high backfill compactness.

This invention relates to the field of foundation construction technology, specifically to a construction method for treating thick, collapsible loess foundations, comprising the following steps: Step 1, construction preparation, including determining the natural moisture content, maximum dry density, and optimum moisture content of the foundation soil and backfill soil, and simultaneously watering and mixing the backfill soil for material preparation; Step 2, drilling humidification holes, injecting filter material into each humidification hole after drilling, and then tamping and backfilling; Step 4, after tamping and backfilling, leveling the construction site, watering and moistening it, and after the piles are formed in the pile holes, leveling and fully tamping; Step 5, inspection. The treatment method provided by this invention has a better effect in eliminating collapsibility, resulting in higher foundation bearing capacity, more uniform overall stiffness, smaller settlement deformation, and an effectively shortened construction period, forming a high-bearing-capacity composite foundation.

The present invention discloses an in-situ test method for the compaction performance of moraine soil containing boulders, and the steps are as follows: A. Sampling and calculating the gravel content: taking soil samples on-site from the compacted subgrade of moraine soil containing boulder components; B. Calculating the dry density of the soil and gravel parts: calculating the dry density of the soil and gravel; C. Measuring the resistivity of the soil part indoors: using a sample press method to prepare cylindrical compacted samples of moraine soil with different dry densities; D. Calculating the relationship between the dry density and resistivity of the soil part; E. Measuring the resistivity of the compacted subgrade of moraine soil on-site: using the four-electrode method to conduct on-site resistivity measurement on the compacted subgrade of moraine soil; F. Calculating the overall dry density of the on-site soil material; G. Measuring the maximum dry density of the on-site soil material; H. Detecting the compaction degree of the moraine soil subgrade. The method is easy to implement and simple to operate, solving the technical problems and difficulties of data distortion and low efficiency in obtaining the dry density and compaction degree of subgrade materials containing boulder particles by the existing methods.

The application discloses a high core wall dam mixed clay tensile-shear fracture test method without friction influence, which comprises the following steps: S1, collecting soil samples and determining the optimal water content and the maximum dry density; S2, designing various test conditions; S3, combining a front half of a mold and a rear half of the mold; S4, assembling a compaction fracture mold; S5, preparing and compacting the mixed clay soil sample; S6, transferring the compaction fracture mold to a hollow test tank; S7, removing a Z-shaped compaction plate and a rectangular ring wall; S8, suspending the test part of the compaction fracture mold; and S9, carrying out the tensile fracture test or the shear fracture test of the mixed clay of the core wall. In the application, the tensile fracture and the shear fracture characteristics of the mixed clay can be studied on the same test device, and the friction does not need to be considered. The application fundamentally solves the problem that the existing soil body fracture test method cannot be used for determining the fracture characteristics of the mixed clay of the high core wall dam, and fills the blank of the test method of the mixed clay of the high core wall dam.

The present invention discloses a testing device and a testing method for a maximum dry density test of sand and soil. The testing device includes a base, a sample container, a fixed platform, a compacting assembly, a vibration assembly, and a control assembly. The sample container is used to hold a soil sample to be tested. The fixed platform is fixedly connected to the base, and the fixed platform is provided with a first fixed groove for installing the sample container. The compacting assembly includes a driving device and a compacting hammer. The driving device is connected to the base, and the compacting hammer is coaxially arranged with the sample container. The driving device drives the compacting hammer to rise. The vibration assembly includes a vibrator and a percussion hammer. The vibrator is installed at the bottom of the fixed platform, and the percussion hammer is installed on the fixed platform. When the vibrator is started, the percussion hammer swings and percusses the side wall of the sample container. The control assembly is electrically connected to the driving device, and the control assembly is electrically connected to the vibration assembly. When compacting the soil sample to be tested, the testing device drives the percussion hammer to percuss the sample container through the vibrator, thereby reducing the porosity of the soil sample and reducing the test error.

The invention discloses preparation of a high-strength low-shrinkage steel slag base mixture and a half-dosage continuous weak vibration construction method. The mixture comprises the following base raw materials in volume ratio: 40%-75% of natural aggregate, 25%-60% of steel slag aggregate, 3.0%-5.0% of cement, and 5.0%-15.0% of fly ash. Wherein the maximum dry density of the mixture is 2.35-2.55 g / cm < 3 >, and the optimal water content is 4.0-6.0%; the 7d unconfined compressive strength of the mixture is greater than or equal to 4.0 MPa; the drying shrinkage coefficient is less than or equal to 120 mu epsilon; during preparation, a grading optimization mechanism for inhibiting the steel slag expansion risk through a physical means is provided; during construction, a continuous weak vibration technology is innovatively adopted to replace traditional strong vibration, high-density steel slag and conventional broken stone synchronously sink at a constant speed in the compaction process, vertical segregation caused by density difference is thoroughly eliminated, structural homogeneity is remarkably improved, and the service life is remarkably prolonged.

This invention relates to the field of engineering waste soil solidification and improvement, and particularly to a method for in-situ modification and solidification of lignin composite solidifying agent. The method includes: uniformly mixing the engineering waste soil to be solidified with cement; calculating the required amount of water to be added according to the optimum moisture content of the engineering waste soil; dissolving water glass and lime in water to generate amorphous calcium silicate, then dissolving sodium lignin sulfonate in the solution; finally, mixing the suspension containing lime, water glass, and sodium lignin sulfonate with the engineering waste soil uniformly; compacting the mixture to its maximum dry density; and curing for at least 7 days. The solidification of engineering construction waste soil using the technical solution of this application has the advantages of low cost, simple operation, high material efficiency, and no secondary pollution.

This invention discloses a method for applying a metal strip multi-point displacement sensor in a roadbed settlement model test, comprising the following steps: Step 1: Soil compaction test: The purpose of determining the optimal moisture content and maximum dry density in the soil compaction test is to detect parameters such as roadbed compaction degree and strength, which plays a very important role in improving the quality of roadbed construction. In this invention, when the roadbed soil undergoes settlement deformation, it causes a change in the fiber Bragg grating of the metal strip multi-point displacement sensor. The demodulator analyzes the drift of the reflected light wavelength of the fiber Bragg grating, and the settlement displacement at multiple points of the sensor can be calculated simultaneously. This solves the problem of objectively and accurately measuring the internal soil settlement deformation in roadbed settlement model tests.

A system for evaluating the strength improvement of the roadbed through bamboo fiber reinforcement, consisting of: a) a material processing unit for producing a soil-bamboo fiber mixture, wherein the bamboo fibers are selected from the group consisting of Barak (Bambusa balcooa), Bari (Bambusa polymorpha), and Mritinga (Bambusa tulda), wherein the fibers have a length of 1.5 cm and a diameter of 2-3 mm and are incorporated at a rate of 3% of the dry weight of the soil; b) a compaction test facility configured to perform the Standard Proctor compaction test to determine the maximum dry density (MDD) and optimal moisture content (OMC); c) a load-bearing capacity test unit configured to perform CBR (California Bearing Ratio) tests, wherein the test unit is designed for CBR tests in both the impregnated and unimpregnated states; d) a subgrade preparation unit configured to prepare a subgrade test section for roadways, comprising layering and compacting the soil-bamboo fiber mixture in 150 mm thick layers to achieve a subgrade thickness of approximately 600 mm; and e) a deflection measuring unit for performing a falling weight deflectometer (FWD) test, wherein the deflection measuring unit comprises seven geophone sensors arranged at intervals of 0 mm, 300 mm, 600 mm, 900 mm, 1200 mm, 1500 mm and 1800 mm from the center of a load plate, and a load cell configured to apply a load of 40 kN.

A method of paving a road including mixing soil beneath a location onto which the road will be paved with water, a coarse aggregate crushing waste (CACW) and cement in the form of a powder to form prepared soil and paving over the prepared soil to form a paved road. Furthermore, the prepared soil includes 5 to 20 wt. % of the CACW, and 0.1 to 5 wt. % of the cement, based on the total weight of the soil. Moreover, the prepared soil has a maximum dry density of at least 2.2 grams per cubic centimeter (g / cm3) and an unconfined compression strength of at least 1100 kilopascals (kPa).

The application relates to the technical field of test analysis, in particular to an intelligent detection method for the compaction degree of fine-grained soil. The method comprises the following steps: collecting the liquid limit, plastic limit, optimal moisture content and maximum dry density of the soil body; collecting the vibration signal at each time of rolling, determining the soil type mutation point and the measurement point according to the characteristics of the vibration signal, and collecting the soil wet density and moisture content of the measurement point; determining the soil stiffness index based on the vibration signal characteristics between the soil type mutation points and the moisture content of the measurement point, and completing the soil division of the measurement point; obtaining the compaction degree; correcting the initial compaction degree correction factor based on different rolling times to obtain the compaction degree correction factor; correcting the compaction degree of the soil with different stiffnesses based on the liquid limit, the plastic limit, the optimal moisture content, the moisture content of the measurement point and the compaction degree correction factor, and completing the compaction degree detection. The application improves the accuracy and efficiency of the compaction degree detection.

The invention discloses a method for accurately determining the rolling dry density of a gravel material through numerical simulation, and provides a method for accurately determining the rolling dry density by performing model simulation by utilizing truncation grading and then compensating a simulation result, so that not only is the operation efficiency of model simulation ensured, but also an accurate simulation result is obtained, and the calculation efficiency is improved. The calculation efficiency and accuracy of determining the dry rolling density of the gravel material through numerical simulation are effectively improved; after the simulation result of the truncation grading is obtained, the pores are compensated through theoretical calculation, the maximum dry density value after compensation is calculated, then the maximum dry density value after compensation is compared with the maximum dry density value of a field rolling test, and the accuracy of the compensation method is verified. According to the method, the gravel material rolling dry density is accurately determined by utilizing numerical simulation, and the calculation precision and the calculation efficiency are both considered.

This invention discloses a method and apparatus for preparing precast piles from engineering waste soil. The waste soil is sieved according to particle size. Based on the particle size composition of the waste soil, particle flow numerical simulation is used to simulate the compaction characteristics of waste soil with different particle sizes under ideal conditions, obtaining the maximum compaction density and gradation. Based on the maximum compaction density gradation under ideal conditions and the characteristic particle size of the cementitious material, different amounts of cementitious material are added to prepare the waste soil mixture. According to the evolution model of compaction density with pressure, the close packing gradation of the waste soil and cementitious material mixture is obtained. Experiments are conducted on the variation of compaction dry density with moisture content, clay mineral content, and cementitious material water demand under different pressure conditions. Based on a multi-parameter artificial neural network machine learning model, a model of dry density with moisture content, clay mineral content, and cementitious material water demand is constructed to obtain the optimal moisture content and maximum dry density under different pressure conditions. A variable frequency micro-amplitude vibration bidirectional compaction device is used for compaction and molding using a four-stage process: static pressure-strong vibration-weak vibration-static pressure.

The invention relates to the technical field of civil engineering materials, and discloses flow-state solidified soil as well as a preparation method and an application construction method thereof. The flow-state solidified soil comprises muck and a modified material, wherein the modified material comprises a main cementing material and an exciting agent; the muck is low-liquid-limit silt with the optimal water content of 16.3% and the maximum dry density of 1.742 g / cm < 2 >; the main cementing material comprises cement, fly ash, mineral powder and desulfurized gypsum; the exciting agent is selected from at least one of sodium silicate and calcium oxide compounded sodium carbonate. The coal ash, the mineral powder, the desulfurized gypsum and other solid wastes are effectively utilized, so that the defects that single cement modification only depends on cement hydration, the cementing efficiency is low and the carbon emission is high are overcome. According to the preparation method of the flow-state solidified soil, the obtained flow-state solidified soil is high in stability and high in compressive strength through the steps of muck pretreatment, modified material mixing and composite stirring, and the unconfined compressive strength of a prepared test piece after the prepared test piece is cured for 56 days reaches 11.2 MPa.

The present invention discloses a device and method for measuring the maximum dry density and bearing ratio of rock and soil. The measuring device includes a compaction system and a penetration system. A positioning sleeve is placed on the top of the sample in the compaction cylinder, a limit plate is provided above the positioning sleeve, and multiple tangential longitudinal positioning channels are provided inside the positioning sleeve. A rotating disk is provided above the positioning sleeve, and multiple hammers are installed on the bottom of the rotating disk through a hammer rod, and the hammers match the positioning channels. The top of the rotating disk is connected to the force-bearing end of the lever. The penetration device includes a penetration rod, the outer wall of the penetration rod is provided with a thread, a horizontal bevel gear is threadedly connected to the penetration rod, the horizontal bevel gear is meshed with the vertical bevel gear, the vertical bevel gear is connected to the rocking plate, and the outer shell is fixedly connected to the base of the compaction system. The present invention integrates two different test devices with obvious conflicts in spatial distribution into one device, saves the time of switching instruments on the basis of ensuring the accuracy of the test, simplifies the test steps, and improves the test efficiency.

The present invention proposes a model, method, and model construction method for estimating the modulus of resilience of MICP-modified expansive soil. The model constructed by the present method comprehensively considers the effects of the number of MICP treatments, maximum dry density, optimal moisture content, plasticity index, CBR, free expansion rate, expansion force, cohesion, internal friction angle, confining pressure, and deviatoric stress. Furthermore, the model has clear physical meaning and a simple structure. The required parameters can be obtained simply through a series of basic indoor tests, greatly reducing experimental time and difficulty. This provides significant engineering benefits for organizations lacking triaxial testing conditions and has high market value. Compared with existing methods, the model and method of the present invention can conveniently and accurately obtain the modulus of resilience of MICP-modified expansive soil under different conditions, more conveniently guiding the design and construction of MICP-modified expansive soil in road structures.

The present invention belongs to the technical field of foundation reinforcement, and specifically discloses a method for estimating the tamping depth, which includes obtaining the original density, original stress and tamping stress of the soil at each of multiple depths at a preset horizontal distance from the tamping point; determining the tamping density of the soil at each depth during the tamping process according to the original density, original stress and tamping stress; and estimating the tamping depth according to the tamping density and the maximum dry density of the soil at the corresponding depth. When determining the tamping depth, the present invention does not require sampling and excavation of the foundation after tamping, so it will not cause the soil to loosen after tamping and ensure the safety of subsequent construction. Further, the present invention can quickly estimate the tamping depth and tamping quality, and can avoid engineering risks caused by insufficient tamping treatment depth and unqualified tamping quality.

The invention discloses a preparation method of a cement-stabilized weathered granite pavement base material. The preparation method comprises the following steps: carrying out property detection on raw materials; based on the principle of a Bailey method, the mixing proportion of mineral aggregates of all specifications is determined; carrying out a compaction test on the mixture of the carbide slag, the cement and the graded broken stone, determining the optimal water content and the maximum dry density of the mixture under different cement dosages, and further determining the optimal water consumption; 7-day unconfined compressive strength under different cement dosages is measured through an unconfined compressive strength test, and a proper cement dosage is selected by comparing strength representative values; uniformly mixing the raw materials according to the determined matching proportion of the mineral aggregates with various specifications, the optimal water consumption and the cement dosage, and doping anionic emulsified asphalt to obtain the cement-stabilized weathered granite pavement base material. The proportion design of the coarse and fine aggregates is optimized by adopting the Bailey method principle, and the anionic emulsified asphalt and the carbide slag are doped, so that the adhesive property and the mechanical property of the weathered granite base material are remarkably improved.

The invention discloses a preparation method of a remolded sample for reducing in-situ mechanical properties of sandy soil based on a static sounding test. The method comprises the following steps: carrying out the static sounding test to obtain conical tip resistance; calculating the in-situ relative density of the sand through an empirical formula; after drilling sampling, obtaining the maximum dry density, the minimum dry density and the natural water content through an indoor soil test; inversely calculating the in-situ dry density through the in-situ relative density, the maximum dry density and the minimum dry density; calculating the in-situ wet density through the in-situ dry density and the natural water content; and preparing the remolded sample by taking the wet density as a target control index. Compared with the prior art, the static sounding test data and the remolding sample preparation process system are combined for the first time, the target density directly derives from in-situ testing, the in-situ state is scientifically restored, the representativeness is high, operation is easy and convenient, cost is low, and the principle is clear; the process standardization is suitable for various engineering investigation and scientific research projects, is easy to popularize and apply in engineering practice, and is especially suitable for sandy soil environments such as oceans, riverbeds and loose settled layers in which undisturbed samples are difficult to obtain.

The present invention discloses a VVTM design method for recycled aggregate from waste concrete stabilized with brick dust and cement. The design utilizes the specimen vertical vibration molding method (VVTM) and includes steps such as raw material testing, aggregate gradation design, determination of the optimal brick dust dosage, optimal moisture content and maximum dry density, and cement dosage. Practical data indicates that the strength of the cement-stabilized recycled aggregate from waste concrete obtained by the present invention meets the design requirements for road bases of various grades. It can replace traditional cement-stabilized crushed stone in semi-rigid road bases, transforming construction waste into valuable resources and contributing to the ecological, environmentally friendly, and orderly development of highway construction.

The application discloses a kind of rockfill material field maximum dry density determination method and related device considering similar gradation scale effect.The method first obtains field original gradation, determines field maximum particle size, indoor allowable maximum particle size and original over-diameter particle content P1;Similar scale multiple n is set to construct similar gradation curve, and the over-diameter content P2 after scaling is counted;According to whether P2 is greater than 30%, the equivalent coarse particle content P is determined in segments: when P2≤ 30%, P=P2 is taken, when P2> 30%, P=P1 / n is taken;Finally, the maximum dry density obtained by indoor compaction test is converted into field maximum dry density by density conversion formula.The size effect is quantitatively corrected by introducing scale multiple n, the system deviation of indoor test density "virtual height" is eliminated, the calculation precision of rockfill material field maximum dry density is significantly improved, and is suitable for two kinds of scale process of pure similar gradation method and mixed method.

The invention belongs to the technical field of road paving, and particularly discloses a construction method for large-thickness paving of a cement-stabilized gravel base layer, which comprises the following steps: screening a gravel material, controlling the ratio of cement to the gravel material during mixing, controlling the water content to be 4.77%, adding water according to the environment temperature, controlling the maximum dry density to be 2.365 g / m < 3 >, and constructing an earth shoulder during paving. Controlling the thickness and the speed of virtual paving by paving, rolling by using road rollers with different tonnages, finishing the surface until no wheel mark exists after initial pressing, re-pressing and final pressing, then performing depth detection, and finally performing film covering and watering maintenance; by strictly controlling the content of raw materials and cement, the water content, the maximum dry density, the paving thickness and grinding, shrinkage cracks caused by sudden change of water gradient are reduced, so that the problems that the water evaporation speed of the raw materials of the cement-stabilized base layer in an arid climate region is too high in the subsequent construction stage, the shrinkage cracks appear on the cement-stabilized base layer, and the construction quality is influenced are solved. Therefore, the strength is reduced.

The invention relates to the technical field of test analysis, in particular to an intelligent detection method for the compaction degree of fine-grained soil. The method comprises the steps that the liquid limit, the plastic limit, the optimal water content and the maximum dry density of a soil body are collected; collecting a vibration signal during each rolling, determining a soil body type mutation point and a measurement point according to the characteristics of the vibration signal, and collecting the soil body wet density and the moisture content of the measurement point; determining a soil mass stiffness index based on the vibration signal characteristics between the soil mass type mutation points and the water content of the measurement points, and completing soil mass division of the measurement points; the compaction degree is obtained; correcting the initial compaction degree correction factor based on different rolling times to obtain a compaction degree correction factor; the compaction degree of the soil bodies with different rigidities is corrected through the liquid limit, the plastic limit, the optimal water content, the water content of the measuring point and the compaction degree correction factor, and compaction degree detection is completed. According to the invention, the accuracy and efficiency of compactness detection are improved.