60 results about "Maximum dry density" patented technology

The invention discloses a backfill soil foundation compaction quality on-site detection method and system. The method comprises the steps that instantaneous acceleration signals of a vibrating wheel in the soil compaction construction process are collected in real time through a three-axis acceleration sensor; the acceleration signal comprises a three-axis acceleration component; recording the number of construction times through construction equipment, collecting position information of a construction area by using a GPS (Global Positioning System), and synchronously binding the acceleration signal with the number of construction times and the position information through timestamps to form a data set corresponding to the position of the construction area; performing spectral analysis on the acceleration signal in the data set, and extracting a dominant frequency amplitude and a first harmonic amplitude to generate a filtered acceleration signal; the filtered acceleration signals are input into a training single-hidden-layer BP neural network, and the soil dry density is calculated in combination with the number of construction times; based on the ratio of the calculated soil dry density to the standard maximum dry density, the soil compactness in the construction area is determined in combination with the position information, and a construction area compactness distribution diagram is generated through the upper computer to optimize the construction strategy.

The invention provides a sludge solidified soil permeability optimization method, and belongs to the technical field of soil permeability, and the method comprises the following steps: collecting multiple layers of sludge samples, and carrying out detailed physical and chemical characterization on the multiple layers of sludge samples, including water content, granularity, specific surface area and other indexes; and determining sludge solidified soil samples with different proportions by adopting a curing agent dosage equation set according to a characterization result. The optimal water content, the maximum dry density and the permeability coefficient of each sample are obtained through a standard compaction test and a variable head permeability test. And establishing a relation model of the sludge solidified soil ratio and the permeability coefficient by utilizing multiple regression analysis, and identifying key factors influencing the permeability. Based on key factors, designing and optimizing an experimental scheme, adjusting the type and dosage of a curing agent, preparing an optimized sludge solidified soil sample, and verifying the improvement of the permeability coefficient. According to the method, the permeability of the sludge solidified soil can be effectively optimized, and the problems that a sludge solidification formula is difficult to optimize and the permeability of a solidified product is difficult to improve in the prior art are solved.

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 relates to a manufacturing method of a roadbed material based on high-water-content tailing soil, and belongs to the field of road engineering and environmental geotechnical engineering. The roadbed material comprises high-water-content tailing soil, lime, cement and water; the preparation method comprises the following steps: crushing the high-water-content tailing soil, and measuring the initial water content of the high-water-content tailing soil; the method comprises the following steps: fully mixing high-water-content tailing soil with lime in different mass ratios, carrying out a lime precipitation test, crushing the tailing soil subjected to lime reaction, fully mixing the crushed tailing soil with cement and water in different mass ratios, carrying out a compaction test, and measuring the optimal water content and the maximum dry density under different cement dosages; according to the optimal water content and the maximum dry density, a California bearing ratio test is carried out, and the optimal cement mixing amount is preferably selected; and producing the high-water-content tailing soil roadbed material. According to the method, the quicklime is adopted for carrying out precipitation pretreatment on the high-water-content tailing soil, and compared with a drying method in a laboratory, the feasibility in large-scale industrial production is higher.

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 relates to the field of solid waste resource utilization, and discloses a method for preparing cement-stabilized bottom ash gravel by using incineration bottom ash artificial aggregate, which comprises the following steps: pretreatment of incineration bottom ash: taking the part with the particle size of less than 4.75 mm as fine aggregate, and preparing the part with the particle size of greater than 4.75 mm into artificial coarse aggregate through ball milling; mixing the incineration bottom ash, a cementing material and water according to a proportion, and preparing artificial aggregate by adopting a cold bonding process through a disc granulator; performing water bath maintenance on the prepared artificial aggregate to form aggregate with certain strength; finally, the artificial aggregate, the incineration bottom ash fine aggregate, the natural aggregate and cement are mixed according to the mixing proportion, and the cement-stabilized bottom ash gravel is prepared through the design of the optimal water content and the maximum dry density. By optimizing the particle size distribution and interface transition zone characteristics of the artificial aggregate, the mechanical property, durability and environmental friendliness of the base material are improved, the production cost and carbon emission are reduced, and high-valued utilization of solid waste is realized.

The invention discloses a red clay improver and a red clay improvement method. The red clay modifier comprises rice hull ash and carbide slag. The improvement method of the red clay comprises the step of mixing the rice hull ash and the carbide slag with different mixing amounts with the red clay according to the optimal proportion. Obtaining the maximum dry density and the optimal water content of the mixed improved soil of each mixing amount; according to the maximum dry density and the optimal water content, the improved soil is prepared into multiple test pieces, and curing is conducted for 28 days; carrying out related mechanical property tests on the test pieces; and determining the optimal mixing amount of the rice hull ash and carbide slag improved red clay according to the mechanical property test result. According to the method, the unconfined compressive strength, the shear strength and the compression performance of the red clay can be remarkably improved, the improved materials are all industrial solid waste materials, the materials are convenient to obtain and low in cost, environmental pollution can be reduced, and the method is particularly suitable for solving the practical engineering problem in the red clay area.

The invention discloses a method for judging collapsibility of silty-fine sand. The method specifically comprises the following steps: step 1, carrying out a standard penetration test on site and obtaining a target soil layer depth and a hammering number; 2, taking a soil sample from the standard penetration test, carrying out an indoor moisture content test to obtain a moisture content value, and carrying out a relative density test to obtain the maximum dry density and the minimum dry density; 3, establishing a relational expression among the hammering number N of the target soil layer, the relative compactness and the dry density according to an on-site standard penetration test, and substituting the hammering number, the water content, the depth of the target soil layer, the maximum dry density and the minimum dry density value into the relational expression to obtain the dry density of the target soil layer; 4, carrying out an indoor remolded soil collapsibility characteristic test, establishing a multiple linear regression prediction formula, substituting the moisture content value and the dry density, obtaining a collapsibility coefficient delta s of the silty-fine sand soil layer, and determining the collapsibility grade of the silty-fine sand; according to the method, the collapsibility of the silty-fine sand can be accurately judged on site.

The invention discloses a roadbed soft rock filler crushing value estimation method considering the content of coarse and fine particles, which comprises the following steps: S1, for a filled soft rock filler roadbed, determining the compaction dry density rho d by adopting a sand filling method, and determining the maximum dry density through an indoor compaction test to obtain a compaction coefficient; s2, performing a particle screening test on the roadbed soft rock filler to obtain the ratio of the mass of coarse particles with the particle size not smaller than 2.5 mm to the total mass; s3, through a point load test, measuring the point load strength of coarse-particle rocks in not less than 6 soft rock fillers, and obtaining the uniaxial compressive strength of the rocks and the average value of the uniaxial compressive strength of the rocks; and S4, estimating the crushing value of the roadbed soft rock filler according to the compaction coefficient of the roadbed soft rock filler, the mass ratio of the coarse particles and the average value of the uniaxial compressive strength of the rock blocks. According to the method, the influence of the strength of the coarse particle rock, the proportion of coarse and fine particles and the compaction density on the crushing value can be comprehensively considered. The test verifies that the method has good applicability.

The invention discloses a stockpiling field construction quality control method, which comprises the following steps of S1, dividing a stockpiling field into a finite element network through three-dimensional coordinates, calculating the stockpiling amount and node coordinates of each unit by combining a compaction degree requirement, an earthwork loose stockpiling density and an earthwork maximum dry density, and establishing a construction control network model; s2, taking the center coordinate of the bottom of the excavator and the vehicle inclination angle as a detection surface and a detection surface inclination angle respectively; the coordinates between the teeth of the excavator bucket and the vehicle inclination angle serve as a working face and a working face inclination angle respectively. During construction, the center point coordinates and the inclination angles of the vehicle working surface and the detection surface are calculated in combination with vehicle satellite real-time positioning signal analysis and inclination angle analysis, construction optimization suggestions and measures are provided for over-filling and under-filling of the detection surface, and the construction quality of the stockpiling yard is ensured.

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 invention relates to the technical field of field foundation soil exploration, in particular to a roadbed compactness detection method, device and system.The roadbed compactness detection method comprises the steps that the wet weight of a soil sample at a roadbed experiment site after repeated hammering and the dry weight of the soil sample after further drying are obtained and used for determining the current dry density of the soil sample; the method comprises the following steps: acquiring a density sequential sequence, a humidity sequential sequence, a pressure sequential sequence and a pressure sequential sequence in a repeated hammering process of a soil sample to determine the current fitting weight of the soil sample, adjusting the water content of the soil sample, and performing weighted curve fitting on dry densities of the soil sample under different water contents according to the fitting weights of the soil sample under different water contents to obtain a weighted curve of the dry densities of the soil sample under different water contents. Therefore, the maximum dry density is obtained and is used for determining the compaction degree of the soil sample. According to the method, the more accurate fitting curve is generated, so that the subgrade compactness detection precision is improved.

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 relates to the technical field of on-site basic soil survey, and specifically relates to a subgrade compaction degree detection method, device and system, including: obtaining the wet weight of the soil sample at the subgrade experiment site after repeated hammering and the dry weight after further drying to determine the current dry density of the soil sample; obtaining the density time series, humidity time series, pressure time series and applied pressure time series during the repeated hammering of the soil sample to determine the current fitting weight of the soil sample; adjusting the water content of the soil sample, and performing weighted curve fitting on the dry density of the soil sample at different water contents according to the fitting weights of the soil sample at different water contents, so as to obtain the maximum dry density and determine the compaction degree of the soil sample. The present invention generates a more accurate fitting curve to improve the accuracy of subgrade compaction degree detection.

The invention discloses a VVTM design method of brick powder doped cement stabilized waste concrete recycled aggregate, which adopts a test piece vertical vibration molding method (VVTM) design, and comprises the steps of raw material inspection, aggregate gradation design, optimal brick powder doping amount determination, optimal moisture content and maximum dry density determination, cement dosage determination and the like. Practice data shows that the strength of the cement-stabilized waste concrete recycled aggregate designed by the invention can meet the design requirements of various grades of road bases, and the cement-stabilized waste concrete recycled aggregate can replace traditional cement-stabilized macadam to be used for a road semi-rigid base, so that the construction waste is turned into wealth, and ecological environmental protection and cyclic and ordered development of road construction are assisted.

The invention discloses a high-core wall dam gravel-doped clay tensile-shear fracture test method without friction influence. The method comprises the following steps: S1, collecting a soil sample and measuring the optimal moisture content and the maximum dry density; s2, designing a plurality of test working conditions; s3, the die front half part and the die rear half part are combined; s4, the compaction fracture mold is assembled; s5, preparing and compacting a gravel-doped clay sample; s6, transferring the compaction fracture mold to a hollow test tank; s7, the Z-shaped compaction plate and the rectangular ring wall are removed; s8, suspending the test part of the compaction fracture mold; and S9, carrying out a tensile fracture test or a shear fracture test on the core-wall gravel-doped clay. According to the test method, the tensile fracture and shear fracture characteristics of the gravel-doped clay can be researched on the same test device, and friction does not need to be considered. The problem that an existing soil body fracture test method cannot be used for measuring the fracture characteristics of the gravel-doped clay of the high-core wall dam is fundamentally solved, and the blank of the test method for the gravel-doped clay of the high-core wall dam is filled up.

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.

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 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.

The invention relates to the technical field of construction technologies, and discloses a high-fill track foundation filling construction method, which comprises the following steps: summarizing related improved soil backfilling mix proportion parameters through laboratory tests, and issuing a related improved soil backfilling mix proportion report through a laboratory; according to the filling construction method for the high-liquid-limit soil red clay improved backfill high-fill track foundation, by considering from the aspect of compaction filling, the optimal proportion of cement-doped improved red clay is 5%, it is proved that the compaction performance of the red clay can be changed by adding a certain amount of cement into the red clay, and the compaction performance of the red clay can be changed by adding 5% of cement into the red clay. The maximum dry density of the red clay can be increased from 1.1. 76 g / cm < 2 > to 1.82 g / cm < 2 >, so that the cement improves the compaction performance of the red clay, the effect is good, the liquid plasticity of the improved red clay meets the standard bearing capacity, strength and deformation requirements, outsourcing of earthwork is not needed, the red clay in the local area can be reasonably utilized, the engineering cost is reduced, and the construction efficiency is improved. And the damage to the natural environment is reduced.

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.