Salinized soil roadbed structure, construction method and construction equipment

Abstract

The invention relates to the technical field of roadbed construction, and discloses a salinized soil roadbed structure, a construction method and construction equipment. The lower cushion layer is arranged on the gravel filling layer and comprises 15% of fly ash, 0.35% of fiber and the balance of improved saline soil; the composite geomembrane is arranged on the lower cushion layer; and the upper cushion layer is arranged on the composite geomembrane and comprises 10% of fly ash and the balance of improved saline soil. Part of gravel packing is replaced by the lower cushion layer, the composite geomembrane and the upper cushion layer, and the cost of the gravel packing can be saved. Fly ash is doped into the upper cushion layer, fly ash and fibers are doped into the lower cushion layer, and the fly ash can reduce the dissolving and sinking rate of the salinized soil and improve the shearing strength of the roadbed; the fibers can be interwoven in the lower cushion layer to form a network, the tensile strength and compressive strength of the roadbed are remarkably improved, meanwhile, the fibers have good water and salt absorption performance, the dissolution proportion of salt can be increased, the salt is gathered on the surface of the lower cushion layer, and the compressive strength of the roadbed is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of roadbed construction, in particular to a saline soil roadbed structure, a construction method and a construction equipment. BACKGROUND

[0002] In the process of highway roadbed and railway roadbed construction, saline soil construction environment is often encountered. Since saline soil has a high salt content and has problems such as dissolution, salt expansion and corrosion, it is necessary to treat the saline soil before roadbed construction.

[0003] The existing treatment method is generally to excavate the saline soil and replace it with gravel fillers, and then to flatten it before roadbed construction. However, in actual construction process, it is difficult and costly to transport a large amount of gravel fillers. Some projects propose to use improved saline soil as a filler backfill (improved saline soil is saline soil with reduced salt content through chemical, physical or other means), but generally have problems of insufficient compressive strength and unstable roadbed height.

[0004] In addition, the existing roadbed construction method generally divides the replacement area into multiple squares of the same area using a white line, then quantitatively deposits fillers in each square, and then flattens it using an excavator or a road roller, which is low in efficiency.

[0005] Therefore, how to provide an efficient construction method for a saline soil roadbed structure using improved saline soil as a filler backfill is a problem to be solved by those skilled in the art. SUMMARY

[0006] The present application aims to provide a saline soil roadbed structure, a construction method and a construction equipment to solve the problems existing in the prior art.

[0007] To achieve the above-mentioned purpose, the present application provides a saline soil roadbed structure, comprising:

[0008] a gravel fill layer;

[0009] a lower cushion layer disposed on the gravel fill layer, containing 15% fly ash and 0.35% fiber, and the rest being improved saline soil;

[0010] a composite geomembrane disposed on the lower cushion layer;

[0011] an upper cushion layer disposed on the composite geomembrane, containing 10% fly ash and the rest being improved saline soil.

[0012] Further, the thickness of the lower cushion layer is 5 cm, and the thickness of the upper cushion layer is 10 cm.

[0013] Further, the composite geomembrane is disposed above the ground surface by 0.6 m or above the highest ground water level by 0.5 m.

[0014] The application also provides a construction method of a saline soil roadbed structure, which is used for constructing a saline soil roadbed structure and comprises the following steps:

[0015] S1: putting a chemical agent into the saline soil foundation and stirring in situ to obtain improved saline soil;

[0016] S2: excavating the improved saline soil from the saline soil foundation to the outside to form a backfill pit;

[0017] S3: filling the backfill pit with gravel fill to form a gravel fill layer;

[0018] S4: after the gravel fill layer is flattened, filling the upper part of the gravel fill layer with improved saline soil, fiber and fly ash to form a lower cushion layer;

[0019] S5: after the lower cushion layer is flattened, laying a composite geomembrane on the lower cushion layer;

[0020] S6: filling the upper part of the composite geomembrane with improved saline soil and fly ash to form an upper cushion layer; and flattening the upper cushion layer to obtain the saline soil roadbed structure.

[0021] The application also provides a construction device of a saline soil roadbed structure, which is used for constructing a saline soil roadbed structure and comprises the following components:

[0022] A vehicle body has a support plate and a roller, and the roller is rotatably arranged on the lower surface of the support plate;

[0023] A feeding cylinder is arranged on the support plate, and a feeding opening is formed in the top of the feeding cylinder;

[0024] A discharging cylinder is placed on the bottom of the feeding cylinder, and the front end and the rear end of the discharging cylinder are fixedly connected with the inner side wall of the feeding cylinder; a feeding opening is formed in the top of the discharging cylinder, and the feeding opening is in communication with the feeding cylinder; a discharging opening is formed in the bottom of the discharging cylinder, and the support plate is provided with a discharging opening corresponding to the discharging opening;

[0025] A slope is connected with the feeding opening at one end and is inclined upward at the other end and connected with the inner side wall of the feeding cylinder;

[0026] A rotating shaft is rotatably arranged in the feeding cylinder, and the rotating shaft penetrates through the feeding cylinder and the discharging cylinder and is drivingly connected with the roller; when the roller rotates, the rotating shaft rotates synchronously;

[0027] A plurality of rotating plates are uniformly and spacedly arranged along the circumference of the rotating shaft, one end of each rotating plate is fixedly connected with the rotating shaft, and the other end of each rotating plate is close to the inner side wall of the feeding cylinder; two adjacent rotating plates and the inner side wall of the feeding cylinder jointly form a feeding chamber; when the rotating shaft drives the feeding chamber to rotate to a position corresponding to the discharging opening, the feeding chamber is in communication with the discharging opening.

[0028] Further, further comprising:

[0029] The road roller has a front end provided with a road roller drum and a drum frame, and the support plate is located at the front end of the road roller drum and connected with the drum frame.

[0030] Further, further comprising:

[0031] The connecting rod is connected with the drum frame at one end by bolts and fixedly arranged at the tail end of the support plate at the other end.

[0032] Further, further comprising:

[0033] The fly ash tank is vertically arranged on a support fixedly arranged on the support plate, the discharge end of the fly ash tank is located at the bottom, and the discharge end of the fly ash tank is communicated with the powder conveying pipe through a first discharge valve; one end of the powder conveying pipe is communicated with the fan, and the other end penetrates the feeding cylinder and the discharging cylinder and is communicated with the feeding chamber.

[0034] Further, further comprising:

[0035] The fiber tank is vertically arranged on a support, the discharge end of the fiber tank is located at the bottom, and the discharge end of the fiber tank is communicated with the powder conveying pipe through a second discharge valve.

[0036] Further, further comprising:

[0037] The driving shaft penetrates the feeding cylinder and the discharging cylinder and is coaxially connected with the driven wheel;

[0038] The transmission wheel is rotatably arranged on a mounting seat arranged on the support plate, and the transmission wheel is transmissionally connected with the driven wheel through a first belt;

[0039] The first connecting wheel is coaxially arranged outside the transmission wheel, the roller is connected with the driving shaft, the driving shaft is located below the support plate, the second connecting wheel is arranged on the driving shaft, the first connecting wheel and the second connecting wheel are transmissionally connected through a second belt, and the support plate is provided with a through hole corresponding to the second belt.

[0040] The following technical effects are disclosed:

[0041] 1. The invention replaces part of the gravel filler with a double-layer water and salt isolation structure composed of a lower cushion, a composite geomembrane and an upper cushion (lower cushion and composite geomembrane), which can save the cost of gravel filler. Fly ash is mixed in the upper cushion, and fly ash and fiber are mixed in the lower cushion. Fly ash can reduce the dissolution rate of saline soil and improve the shear strength of the roadbed; fiber can interweave to form a network in the lower cushion, significantly improving the tensile strength and compressive strength of the roadbed, and at the same time, fiber has good water and salt absorption, which can increase the dissolution rate of salt, so that salt is concentrated on the surface of the lower cushion, further improving the compressive strength of the roadbed. The improved saline soil is used as the filler for backfilling during the construction of the roadbed.

[0042] 2. The invention provides a saline soil roadbed structure construction equipment for constructing a saline soil roadbed structure. The periodic discharge filler structure formed by the feed cylinder, discharge cylinder, rotating shaft and rotating plate can be used for quantitative feeding of gravel filling, upper cushion filling and lower cushion filling, and the filled soil is flattened by the road roller, which greatly improves the work efficiency compared with the prior art.

[0043] 3. The saline soil roadbed structure construction equipment includes a fly ash tank and a fiber tank, which can blow fly ash and fiber into the feed chamber through the fan. Under the action of the air pressure of the fan and the rotation of the feed chamber, the fly ash and fiber can quickly mix with the improved saline soil, and then form the filler required for the lower cushion or the upper cushion.

[0044] 4. The vehicle body is connected to the road roller through a connecting rod, and the vehicle body is driven to move by the road roller. The road roller only needs to set a screw hole connected with the connecting rod on the roller frame, which has small structural changes to the road roller, simple connection and convenient use.

[0045] 5. The rotating shaft is drivingly connected with the roller through the driven wheel, transmission wheel, first connecting wheel and second connecting wheel, so that the rotating speed of the rotating shaft corresponds to the rolling speed of the roller, and the rotating speed of the rotating shaft directly affects the speed of discharging the filler. Therefore, the invention can realize self-adaptive adjustment of the discharge filler according to the traveling speed of the road roller, guarantee quantitative discharge of the filler, and has good application prospect and wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are only some embodiments of the invention, and other drawings can be obtained by those skilled in the art without creative labor.

[0047] Figure 1 The saline soil roadbed structure structure diagram;

[0048] Figure 2 It is a schematic diagram of the structure of the salted soil subgrade construction equipment;

[0049] Figure 3 It is a schematic diagram of the cooperation of the feeding cylinder and the supporting plate;

[0050] Figure 4 It is a schematic diagram of the transmission cooperation of the rotating shaft and the roller;

[0051] Figure 5 It is a stress-strain curve;

[0052] Figure 6 It is a vertical pressure-solubility coefficient curve;

[0053] Among them, 1, supporting plate; 2, roller; 3, feeding cylinder; 4, feeding port; 5, discharging cylinder; 6, feeding port; 7, discharging port; 8, discharging port; 9, slope; 10, rotating shaft; 11, rotating plate; 12, feeding chamber; 13, road roller; 14, road roller; 15, roller frame; 16, connecting rod; 17, fly ash tank; 18, support; 19, first discharge valve; 20, fiber tank; 21, second discharge valve; 22, powder conveying pipe; 23, driven wheel; 24, transmission wheel; 25, first belt; 26, first connecting wheel; 27, second belt; 28, gravel fill layer; 29, lower cushion layer; 30, composite geomembrane; 31, upper cushion layer; 32, fan. DETAILED DESCRIPTION

[0054] Among the retrieved prior art:

[0055] Patent application CN118727863A discloses a salted soil subgrade rapid replacement device and construction method. In view of the problems of high salt content of salted soil, easy subsidence, salt expansion and corrosion, traditional treatment method needs to replace soil outside, which has high cost, low efficiency and large pollution, a mobile device integrating crushing, conveying, stirring and backfilling is proposed to realize rapid in-situ improvement and replacement of salted soil subgrade.

[0056] The device is carried by a mobile carrier (caterpillar type / wheel type engineering machinery) with three modules:

[0057] The crushing mechanism is installed at the front end of the carrier through a mechanical adjusting arm, and can be lifted, rotated and pitched. It includes:

[0058] Main support: triangular supporting plate (bottom plate + partition plate + buckle plate) + arm guard, with built-in transmission structure.

[0059] Roller: at least 2, with teeth on the surface, counter-rotating to crush soil.

[0060] Drive device: motor / hydraulic motor, driven by gear chain transmission (main gear → first gear → second gear → third gear → fourth gear).

[0061] Cutting teeth: the chain outer periphery is toothed, which helps to break the soil and travel.

[0062] Dust outlet: remove the sand entering the transmission cavity.

[0063] Conveying mechanism; it includes:

[0064] Conveyor belt: foldable design (main support + secondary support), input end connects broken soil, output end to stirring barrel.

[0065] Tensioning device: adjust the roller shaft to prevent belt slip.

[0066] Drive unit: driving roller + motor.

[0067] Stirring mechanism; it includes:

[0068] Stirring barrel: top with feed inlet (connecting conveyor belt), feeding hopper (improving agent), spray head (adding water).

[0069] Stirring paddle: motor driven, mixing soil and improving agent (such as calcium salt, microbial preparation).

[0070] Discharging system: screw shaft + discharge cylinder (length matching the width of the broken), uniform backfill.

[0071] The working principle is as follows:

[0072] Crushing: adjust the mechanical arm to make the roller cut into the soil body, and crush and collect in reverse rotation.

[0073] Conveying: broken soil is continuously sent into the stirring barrel through the conveyor belt.

[0074] Improvement: synchronously add improving agent and water, and stir into homogeneous improved soil.

[0075] Backfilling: the spiral shaft uniformly backfills the improved soil to the original pit through the discharge cylinder.

[0076] As can be seen from the above, the above patent realizes the rapid in-situ improvement and replacement of saline soil subgrade structure, although it integrates crushing, conveying, stirring and backfilling, but still has the problems of insufficient compressive strength of subgrade and unstable height of subgrade. And the equipment in the above patent can only act on a small range in actual use, cannot adapt to large range subgrade filling engineering, and cannot be used with a road roller.

[0077] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0078] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0079] As shown in Figures 1 to 6 , the embodiment of the present application provides a saline soil subgrade structure, comprising:

[0080] a gravel fill layer 28;

[0081] a lower cushion layer 29 disposed on the gravel fill layer 28, containing 15% fly ash and 0.35% fiber, and the rest being improved saline soil;

[0082] a composite geomembrane 30 disposed on the lower cushion layer 29;

[0083] an upper cushion layer 31 disposed on the composite geomembrane 30, containing 10% fly ash and the rest being improved saline soil.

[0084] In this embodiment, the thickness of the lower cushion layer 29 is 5 cm, and the thickness of the upper cushion layer 31 is 10 cm.

[0085] In this embodiment, the composite geomembrane 30 is disposed above the ground surface by 0.6 m or above the highest ground water level by 0.5 m.

[0086] As shown in Figure 5 , stress-strain tests were conducted on the upper cushion layer 31 containing different contents of fly ash, and stress-strain curves were obtained. When the axial strain ε is constant, the axial stress σ increases first and then decreases with the increase of the fly ash content, and reaches the maximum value when the fly ash content is 10%; when the axial stress σ is constant, the axial strain decreases with the increase of the fly ash content; when the fly ash content is 10%, the ultimate stress reaches the maximum value. The stress-strain curve of the saline soil without fly ash has a relatively small failure stress and a large failure strain; after adding fly ash to the saline soil, the slope of the stress-strain curve of the improved saline soil becomes steeper, the failure stress gradually increases with the increase of the fly ash content, and the failure strain gradually decreases.

[0087] As shown in Figure 6The test method is to analyze the relationship between the curing hour maintenance collapse coefficient and the additional load pressure (vertical pressure), the saline soil is selected as the chloro-saline soil, and a vertical pressure-collapse coefficient curve is obtained. It can be seen that the addition of fly ash in the chloro-saline soil can reduce the collapse coefficient, so as to achieve the effect of improving the collapsibility of the saline soil. However, under the condition of different additional load pressure, the change trend of the collapse coefficient of the fly ash improved chloro-saline soil is not the same: first, when the pressure is less than 400 KPa, the collapse coefficient of the fly ash improved chloro-saline soil reaches the minimum value when the mixing ratio is 5%, and the collapse coefficient increases with the increase of the mixing ratio of fly ash; when the pressure is higher than 400 KPa, the collapse coefficient of the fly ash improved chloro-saline soil gradually decreases with the increase of the mixing ratio of fly ash, and the collapse coefficient reaches the minimum value when the mixing ratio is 15%, and the collapse coefficient increases with the increase of the mixing ratio of fly ash. According to the test results, the best mixing amount of fly ash in the upper cushion layer 31 and the lower cushion layer 29 is determined to be 10% and 15% respectively.

[0088] The compressive strength test is carried out on the saline soil containing different contents of fibers, the fiber is selected as polypropylene fiber, and the variables are the salt content of the saline soil and the content of the fiber. The test results show that no matter how much the salt content of the saline soil is, the addition of polypropylene fiber can improve the unconfined compressive strength of the saline soil, and with the increase of the fiber content, the unconfined compressive strength first increases obviously, and when the content is greater than 0.35%, the strength increases gradually. According to the test results, the content of the fiber in the lower cushion layer 29 is determined to be 0.35%.

[0089] The embodiment of the present application also provides a construction method of a saline soil subgrade structure, which is used for constructing a saline soil subgrade structure, and comprises the following steps:

[0090] S1: cleaning the saline soil foundation, pouring chemical agents into the saline soil foundation and stirring in situ to obtain improved saline soil, and the specific operation steps of the improved saline soil can adopt the prior art, which will not be repeated here;

[0091] S2: excavating the improved saline soil from the saline soil foundation to the outside to form a backfill pit;

[0092] S3: filling gravel soil in the backfill pit to form a gravel soil layer 28;

[0093] S4: after the gravel soil layer 28 is flattened, filling the improved saline soil, fiber and fly ash above the gravel soil layer 28 to form a lower cushion layer 29;

[0094] S5: flattening the lower cushion layer 29, and laying a composite geomembrane 30 on the lower cushion layer 29;

[0095] S6: filling the composite geomembrane 30 with the improved saline soil and fly ash to form an upper cushion 31; and flattening the upper cushion 31 to obtain the saline soil subgrade structure.

[0096] The application also provides a saline soil subgrade structure construction device for constructing a saline soil subgrade structure, comprising:

[0097] The vehicle body has a support plate 1 and a plurality of rollers 2 rotatably arranged on the lower surface of the support plate 1, the rollers 2 are arranged in two groups, and each group is arranged near the front end and the rear end of the support plate 1, and the rollers 2 in each group are connected by a drive shaft;

[0098] The feeding cylinder 3 is arranged on the support plate 1, and a feeding port 4 is arranged at the top of the feeding cylinder 3;

[0099] The discharging cylinder 5 is arranged on the bottom of the feeding cylinder 3, and the structure of the discharging cylinder 5 is similar to a bracket, the front end and the rear end of the discharging cylinder 5 are fixedly connected with the inner side wall of the feeding cylinder 3, the feeding port 6 is arranged through the inner and outer surfaces of the top of the discharging cylinder 5, the feeding port 6 is in communication with the feeding cylinder 3, the discharging port 7 is arranged through the inner and outer surfaces of the bottom of the discharging cylinder 5, and the support plate 1 is provided with a discharging port 8 corresponding to the discharging port 7;

[0100] The slope 9 is connected with the feeding port 6 at one end and is connected with the inner side wall of the feeding cylinder 3 at the other end;

[0101] The rotating shaft 10 is rotatably arranged in the feeding cylinder 3, the rotating shaft 10 penetrates the feeding cylinder 3 and the discharging cylinder 5 and is in transmission connection with the rollers 2, and when the rollers 2 rotate, the rotating shaft 10 rotates synchronously;

[0102] A plurality of rotating plates 11 are arranged on the circumference of the rotating shaft 10 at uniform intervals, one end of each rotating plate 11 is fixedly connected with the rotating shaft 10, the other end of each rotating plate 11 is close to the inner side wall of the feeding cylinder 3, and adjacent two rotating plates 11 and the inner side wall of the feeding cylinder 3 jointly form a feeding chamber 12, and when the rotating shaft 10 drives the feeding chamber 12 to rotate to a position corresponding to the discharging port 7, the feeding chamber 12 is in communication with the discharging port 7.

[0103] In the embodiment, the device further comprises:

[0104] The road roller 13 has a road roller cylinder 14 and a roller frame 15 at the front end, the road roller cylinder 14 is rotatably arranged on the inner side of the roller frame 15, and the support plate 1 is located at the front end of the road roller cylinder 14 and is connected with the roller frame 15.

[0105] In the embodiment, the device further comprises:

[0106] The connecting rod 16 is connected with the roller frame 15 at one end through a bolt and is fixedly arranged at the tail end of the support plate 1 at the other end.

[0107] In the embodiment, the device further comprises:

[0108] The fly ash tank 17 is vertically arranged on the support 18, and the support 18 is fixedly arranged on the support plate 1. The discharge end of the fly ash tank 17 is located at the bottom. The discharge end of the fly ash tank 17 is communicated with the powder feeding pipe 22 through the first discharge valve 19. One end of the powder feeding pipe 22 is communicated with the fan 32, and the other end penetrates the feeding cylinder 3 and the discharging cylinder 5 and is communicated with the feeding chamber 12.

[0109] In the embodiment, further comprising:

[0110] The fiber tank 20 is vertically arranged on the support 18. The discharge end of the fiber tank 20 is located at the bottom. The discharge end of the fiber tank 20 is communicated with the powder feeding pipe 22 through the second discharge valve 21.

[0111] The first discharge valve 19 and the second discharge valve 21 are used to control the output of the fly ash and the fiber. In the embodiment, a control system can be further arranged. The control system controls the output of the fly ash and the fiber according to the rotating speed of the rotating shaft 10, so that the fly ash and the fiber are mixed with the modified saline soil in the feeding chamber 12 according to a preset ratio.

[0112] In the embodiment, further comprising:

[0113] The driven wheel 23 is coaxially connected with the driven wheel 23, and the rotating shaft 10 penetrates the feeding cylinder 3 and the discharging cylinder 5.

[0114] The transmission wheel 24 is rotatably arranged on the mounting seat, and the mounting seat is arranged on the support plate 1. The transmission wheel 24 and the driven wheel 23 are drivingly connected through the first belt 25.

[0115] The first connecting wheel 26 is coaxially arranged on the outer side of the transmission wheel 24. The roller 2 is connected with a driving shaft, and the driving shaft is located below the support plate 1. The driving shaft is provided with a second connecting wheel. The first connecting wheel 26 and the second connecting wheel are drivingly connected through the second belt 27. The support plate 1 is provided with a through hole corresponding to the second belt 27.

[0116] The specific working process is as follows:

[0117] The following example of the application of the filler corresponding to the cushion 29, when the road roller 13 moves forward, the road roller 13 pushes the vehicle body to move, the roller 2 and the driving shaft rotate, the driven shaft 23 is rotated through the second belt 27, the first connecting wheel 26, the transmission wheel 24, the driven shaft 23 drives the rotating shaft 10 to rotate, the modified saline soil in the feeding cylinder 3 falls into the feeding chamber 12, and rotates in the counterclockwise direction, when the feeding chamber 12 rotates to the position corresponding to the powder conveying pipe 22, the fan 32 starts to work, at the same time, the first discharge valve 19 and the second discharge valve 21 are opened, the fly ash and the fiber enter the powder conveying pipe 22 according to the preset ratio and are blown into the feeding chamber 12 by the fan 32 to mix with the modified saline soil to form the filler corresponding to the lower cushion 29. When the feeding chamber 12 rotates to the discharge port 7, the filler falls to the ground through the discharge port 7 and the discharge port 8, and is compacted by the road roller 13.

[0118] Application example 1

[0119] The above embodiment is applied to the roadbed engineering of the Jiegantai railway of the Urumqi Railway Bureau Group Co., Ltd. The line is connected to the west end of the Baishihu railway station of the Hongnaomao railway and is introduced into the Jiejunmiao station of the Wujie railway, and the length of the main line is 429.884km. Xinjiang Uygur Autonomous Region is a region with serious soil salinization in China. The soluble salt in the saline soil accumulates in the surface layer of the ground with the upward movement of the capillary water, resulting in soil salt accumulation. Salt immersion intensifies the frost heaving and slurry of the roadbed, and the bearing capacity of the roadbed decreases sharply when it is immersed in water, which is prone to settlement and deformation. Salt expansion causes the roadbed and pavement to swell and crack, the shoulder and slope to be loose and eroded, and the above factors determine that the salt content of the roadbed filler in the saline soil area should be strictly controlled. However, the non-salt soil and weak salt soil in the saline soil area is very small in distribution, the transportation distance is generally far, and the construction water is scarce, so it is difficult to realize the earth borrowing (non-salt soil and weak salt soil) filling. Therefore, it is decided to apply the embodiment to the construction of the saline soil roadbed structure, and the cumulative construction length is 3.545km / 9 sections. After 400,000 times of dynamic load is applied, the roadbed settlement value is stable at 6.03mm, and the compression resistance, tensile strength and shear strength all meet the engineering requirements.

[0120] Application example 2

[0121] The Tamen road is located in the east of the first division Alar city, and is located in the south of Tianshan Mountain, the northwest of Tarim basin. The road width is 20m, the motorway is 8m, the green belt on both sides is 4m, and the non-motorway is 8m. Alar city is located in the saline soil distribution zone, the average annual temperature is 10.8℃, the annual precipitation is 40-100mm, the highest temperature in summer is as high as 39.2℃, the lowest temperature in winter can reach-25.8℃, and the temperature difference is large. The standard frozen soil depth is 80cm, and it belongs to the typical seasonal frozen soil disaster area, so the city road is seriously damaged by the saline soil. Therefore, it is decided to apply the embodiment to the saline soil roadbed structure construction. After the construction, the roadbed is tested, and after 40 million times of dynamic load, the roadbed settlement value is stabilized at 5.68mm, and the compressive strength, tensile strength and shear strength all meet the engineering requirements.

[0122] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation of the present application.

[0123] The above-described embodiments are only used to describe the preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A saline soil roadbed structure, characterized in that: include: Gravel fill layer (28); The sub-base (29) is provided on the gravel fill layer (28) and comprises 15% fly ash and 0.35% fiber, with the remainder being improved saline soil; A composite geomembrane (30) is provided on the underlying layer (29); The upper cushion layer (31) is arranged on the composite geomembrane (30) and contains 10% fly ash and the rest is improved saline soil.

2. The saline soil roadbed structure according to claim 1, characterized in that: The thickness of the lower cushion layer (29) is 5 cm, and the thickness of the upper cushion layer (31) is 10 cm.

3. The saline soil roadbed structure according to claim 1, characterized in that: The composite geomembrane (30) is arranged 0.6 m above the ground or 0.5 m above the highest ground water level.

4. A method for constructing a saline soil roadbed structure, characterized in that: The method for constructing a saline soil roadbed structure according to any one of claims 1 to 3 comprises the following steps: S1: Add chemical agents to the saline soil foundation and stir in situ to obtain improved saline soil; S2: excavating the improved saline soil from the saline soil foundation to the outside to form a backfill pit; S3: Filling the backfill pit with gravel fill to form a gravel fill layer (28); S4: After the gravel fill layer (28) is flattened, improved saline soil, fiber and fly ash are filled above the gravel fill layer (28) to form a base layer (29); S5: After the lower cushion layer (29) is flattened, a composite geomembrane (30) is laid on the lower cushion layer (29); S6: Filling the composite geomembrane (30) with improved saline soil and fly ash to form an upper cushion layer (31); flattening the upper cushion layer (31) to obtain a saline soil roadbed structure.

5. A saline soil roadbed structure construction equipment, characterized in that: Used for constructing a saline soil roadbed structure according to any one of claims 1 to 3, comprising: The vehicle body comprises a support plate (1) and a roller (2), wherein the roller (2) is rotatably arranged on the lower surface of the support plate (1); A feeding cylinder (3) is arranged on the support plate (1) and has a feeding port (4) at the top; The discharge barrel (5) is placed flat on the bottom of the feed barrel (3), and its front and rear ends are fixedly connected to the inner side wall of the feed barrel (3). The top of the discharge barrel (5) is provided with a feed port (6) through the inner and outer surfaces, and the feed port (6) is connected to the feed barrel (3). The bottom of the discharge barrel (5) is provided with a discharge port (7) through the inner and outer surfaces, and the support plate (1) is provided with a discharge port (8) corresponding to the discharge port (7); A slope (9), one end of which is connected to the feed port (6) and the other end of which is inclined upward and connected to the inner wall of the feed barrel (3); A rotating shaft (10) is rotatably disposed in the feed barrel (3), the rotating shaft (10) passes through the feed barrel (3) and the discharge barrel (5) and is transmission-connected to the roller (2), and when the roller (2) rotates, the rotating shaft (10) rotates synchronously; A plurality of rotating plates (11) are evenly spaced along the circumference of the rotating shaft (10), one end of each rotating plate is fixedly connected to the rotating shaft (10), and the other end is close to the inner wall of the feeding barrel (3). Two adjacent rotating plates (11) and the inner wall of the feeding barrel (3) together form a feeding chamber (12). When the rotating shaft (10) drives the feeding chamber (12) to rotate to a position corresponding to the discharge port (7), the feeding chamber (12) is communicated with the discharge port (7).

6. The saline soil roadbed structure construction equipment according to claim 5, characterized in that: Also includes: The roller (13) has a roller (14) and a roller frame (15) at the front end, and the support plate (1) is located at the front end of the roller (14) and connected to the roller frame (15).

7. The saline soil roadbed structure construction equipment according to claim 6, characterized in that: Also includes: A connecting rod (16) has one end connected to the roller frame (15) via a bolt, and the other end fixedly arranged at the rear end of the support plate (1).

8. The saline soil roadbed structure construction equipment according to claim 5, characterized in that: Also includes: A fly ash tank (17) is vertically arranged on a bracket (18), and the bracket (18) is fixedly arranged on the support plate (1). The discharge end of the fly ash tank (17) is located at the bottom, and the discharge end of the fly ash tank (17) is connected to the powder delivery pipe (22) through a first discharge valve (19); one end of the powder delivery pipe (22) is connected to the fan (32), and the other end passes through the feed barrel (3) and the discharge barrel (5) and is connected to the feed chamber (12).

9. The saline soil roadbed structure construction equipment according to claim 8, characterized in that: Also includes: The fiber tank (20) is vertically arranged on the bracket (18), the discharge end of the fiber tank (20) is located at the bottom, and the discharge end of the fiber tank (20) is connected to the powder feeding pipe (22) through the second discharge valve (21).

10. The saline soil roadbed structure construction equipment according to claim 5, characterized in that: Also includes: A driven wheel (23), wherein the rotating shaft (10) passes through the feed cylinder (3) and the discharge cylinder (5) and is coaxially connected to the driven wheel (23); A transmission wheel (24) is rotatably mounted on a mounting seat, wherein the mounting seat is mounted on the support plate (1), and the transmission wheel (24) is connected to the driven wheel (23) via a first belt (25); A first connecting wheel (26) is coaxially arranged on the outer side of the transmission wheel (24); the roller (2) is connected to a driving shaft; the driving shaft is located below the support plate (1); a second connecting wheel is arranged on the driving shaft; the first connecting wheel (26) and the second connecting wheel are connected to each other through a second belt (27); and a through hole is provided in the support plate (1) corresponding to the second belt (27).

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