A method for treating mud and slurry in expansive rock soil roadbed of ballasted railway

Abstract

The present invention discloses a method for treating mud bubbling in ballasted railway expansive rock and soil roadbed, including grading the soil expansion potential of the subgrade according to clay composition and content test data; calculating the average annual precipitation; investigating the mud bubbling degree of the subgrade, and determining the basic characteristics of mud bubbling through statistical analysis; determining the degree of drainage blockage; investigating the wear, direction, height change and triangular pits of the rail surface, and determining the state of the rail; grading the mud bubbling disease according to the calculation results; and determining the corresponding tough and fast-strengthening anti-seepage waterproof protective layer and specific treatment plan according to the mud bubbling disease grade. The present invention improves the overall strength of the subgrade surface layer of the subgrade through a method for constructing a tough and fast-strengthening anti-seepage protective layer on the subgrade surface, blocks the hydraulic connection between atmospheric precipitation and the hydrophilic minerals of the subgrade surface rock and soil, and quickly forms a tough waterproof layer with a certain strength, which is suitable for the rapid construction of existing operating railway lines, and cures the mud bubbling disease from the source of the subgrade.

Description

Technical Field

[0001] The invention relates to a method for treating mud bubbling in ballasted railway expansive rock soil roadbed, and belongs to the technical field of railway construction, maintenance and repair, and new process research and development. Background Art

[0002] In newly built and operated ballasted railways, the subgrade bed directly bears the periodic repetitive vibration load of the upper trains, and is an important part of the subgrade, which directly affects the safety of railway operations. Since the railway is mainly borne by two parallel rails directly by the entire upper train load, the subgrade bears the dynamic load transmitted from the upper part, and there is a long-term uneven linear stress concentration, which leads to a large amount of creep of the subgrade under the rails and the formation of linear long grooves on the path surface.

[0003] Although the relevant specifications strictly stipulate the soil quality and density requirements for the roadbed filler, they are limited by subjective and objective conditions. For example, the early railway design standards were low. As a long-distance linear project, the railway passes through complex terrain, complex rock and soil distribution, and even climate change. In some areas, there is a lack of high-quality fillers or insufficient understanding of the engineering characteristics of the subgrade fill. In addition, the drainage of some sections of the roadbed is not smooth, resulting in the wetting of the subgrade rock and soil of the railway subgrade under the combined action of atmospheric precipitation infiltration and vibration loads, and the expansion of rock soil, clay rock and mud rock weathering products. Hydrophilic minerals absorb cement and accumulate in the trough under the track, which aggravates the muddiness of the subgrade soil. Under the dynamic load of the train, the surface of the subgrade softens and mud splashes or squeezes out of the surface of the ballast, causing mud and slurry in the subgrade. In addition, the speed increase and heavy load requirements of railways this year pose huge risks to the safe operation of newly built and operating railways. Due to the strict requirements of on-site operation management of railway operations, special on-site operating conditions and existing technical means, it is impossible to effectively prevent and quickly cure subgrade diseases. Mud and slurry in the subgrade of existing lines is called the "cancer" of the railway subgrade. Summary of the invention

[0004] In order to overcome the defects in the prior art, the present invention aims to provide a method for treating mud bubbling in expansive rock soil roadbed of ballasted railway.

[0005] The present invention provides a technical solution to solve the above technical problems: a method for treating mud bubbling in ballasted railway expansive rock soil roadbed, comprising the following steps:

[0006] Step S1, conducting a survey and sampling test on the rock and soil characteristics of the roadbed and the main clay mineral components, and taking samples for relevant geotechnical tests and mineral composition and content tests, and classifying the expansion potential of the subgrade soil according to the clay composition and content test data;

[0007] Step S2, investigating the annual precipitation in the railway mud-swelling area and calculating the average annual precipitation;

[0008] Step S3, investigating the degree of mud slurry on the roadbed, and determining the basic characteristics of mud slurry by statistical analysis;

[0009] Step S4, investigating the roadbed drainage situation and determining the degree of drainage blockage;

[0010] Step S5, investigating the rail surface wear, direction, height change and triangular pits to determine the rail status;

[0011] Step S6, assigning values ​​to the above parameters and calculating them, and classifying the mud-swelling diseases according to the calculation results;

[0012] Step S7: determine the corresponding protective layer combination thickness and specific treatment plan according to the mud and mud hazard level.

[0013] A further technical solution is that the expansion potential of the base soil in step S1 includes weak expansion, medium expansion and strong expansion.

[0014] A further technical solution is that the weak expansion refers to slope residual and slope diluvial rock and soil with a free expansion rate of 40 ≤Fs<60, a montmorillonite content of 7≤M<17, and a cation exchange capacity of 170≤CEC<260; the medium expansion refers to alluvial and diluvial rock and soil with a free expansion rate of 60≤Fs<90, a montmorillonite content of 17≤Fs<27, and a cation exchange capacity of 260≤CEC<360; the strong expansion refers to lacustrine rock and soil with a free expansion rate of Fs≥90, a montmorillonite content of M≥27, and a cation exchange capacity of CEC≥360.

[0015] A further technical solution is that the specific process of step S6 is:

[0016] Step S61, determining a first rating factor, a second rating factor, a third rating factor, a fourth rating factor, a fifth rating factor, a sixth rating factor, a seventh rating factor, an eighth rating factor, and a ninth rating factor according to the expansion potential of the subgrade soil, the cause of the subgrade soil, the type of mud overflow, the average annual precipitation, the basic characteristics of mud overflow, the degree of drainage blockage, and the state of the rails;

[0017] Step S62: Calculate the mud boiling disease rating value M by summing up the first rating factor, the second rating factor, the third rating factor, the fourth rating factor, the fifth rating factor, the sixth rating factor, the seventh rating factor, the eighth rating factor, and the ninth rating factor. 10 ;

[0018] Step S63: According to the mud oozing disease rating value M 10 To classify into levels.

[0019] A further technical solution is that the classification in step S63 is specifically as follows: when the mud boiling disease rating value M 10When it is less than 160, the mud-overflowing disease is assessed as weak;

[0020] When the mud oozing disease rating value is M 10 When it is greater than or equal to 160 and less than 280, the mud and mud disease is rated as medium;

[0021] When the mud oozing disease rating value is M 10 When it is greater than or equal to 280, the mud and slurry disease is assessed as severe.

[0022] A further technical solution is that in step S7, when the mud oozing disease is assessed as weak, a 3 cm thick consolidation layer of modified nano gelling agent and washed stone chips mixed in an optimal ratio is constructed using the surface layer of the roadbed, and a 3 mm thick modified nano gelling agent cured coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer with a certain strength, and medium-coarse sand of not less than 3 cm is laid on the anti-seepage patch, wherein the consolidation layer, the tough waterproof layer, and the medium-coarse sand form a three-layer protective layer structure, and the strength of the consolidation layer reaches more than 50 KPa within 5-10 minutes;

[0023] When the mud oozing disease is assessed as medium, a 6cm thick consolidation layer of modified nano gelling agent and washed stone chips mixed in the best proportion is constructed on the surface of the roadbed. A 3mm thick modified nano gelling agent cured coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer with a certain strength. Medium-coarse sand of not less than 3cm is laid on the anti-seepage patch. The consolidation layer, tough waterproof layer and medium-coarse sand form a three-layer protective layer structure. The strength of the consolidation layer reaches more than 50KPa within 5-10 minutes.

[0024] When the mud and slurry disease is assessed to be serious, a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion is constructed on the surface of the roadbed. A 2mm thick modified nano-gelling agent cured coating anti-seepage patch is laid on the consolidation layer. A 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion is constructed on the anti-seepage patch. A 3mm thick modified nano-gelling agent cured coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer with a certain strength. The anti-seepage patch is spread with not less than 3cm of medium-coarse sand, among which the consolidation layer, modified nano-gelling agent cured coating anti-seepage patch, consolidation layer, tough waterproof layer and medium-coarse sand form a five-layer protective layer structure, and the strength of the consolidation layer reaches more than 50KPa within 5-10 minutes.

[0025] A further technical solution is that, in step S7, when the mud oozing disease is assessed as weak, the corresponding specific treatment plan is:

[0026] Step 1: clean and remove the ballast, mud on the surface of the subgrade and the muddy and weak subgrade;

[0027] Step 2: Lay a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion, make a 4% drainage slope, and lay a single-line laying width of 5 meters, 2.5 meters on both sides of the line center; the double-line laying width is half the line spacing width + 2.5 meters;

[0028] Step 3: Lay a modified nano-gelling agent cured coating anti-seepage patch with a thickness of 3 mm and a width of ≥ 1 m, with the patch overlap not less than 5 cm;

[0029] Step 4: Spread 3-5cm of surface sand and level it with a sand scraper;

[0030] Step 5: paving ballast, raising the track, repairing and restoring the line;

[0031] Step 6: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is rainfall flooding the roadbed, deepen and widen the drainage side ditches. Deepen the side ditches in groundwater road cuttings and set up water collection wells in the side ditches when necessary.

[0032] A further technical solution is that, in step S7, when the mud boiling disease is assessed as medium, the corresponding specific treatment plan is:

[0033] Step 1: clean and remove the ballast, mud on the surface of the subgrade and the muddy and weak subgrade;

[0034] Step 2: Lay a 6cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion, make a 4% drainage slope, and lay a single-line 5m wide, 2.5m on each side of the line center; double-line laying width is half the line spacing width + 2.5m;

[0035] Step 3: Lay a modified nano-gelling agent cured coating anti-seepage patch with a thickness of 3 mm and a width of ≥ 1 m, with the patch overlap not less than 5 cm;

[0036] Step 4: Spread 3-5cm of surface sand and level it with a sand scraper;

[0037] Step 5: paving ballast, raising the track, repairing and restoring the line;

[0038] Step 6: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is rainfall flooding the roadbed, deepen and widen the drainage side ditches. Deepen the side ditches in groundwater road cuttings and set up water collection wells in the side ditches when necessary.

[0039] A further technical solution is that, when the mud oozing disease is assessed as serious in step S7, the corresponding specific treatment plan is:

[0040] Step 1: clean and remove the ballast, mud on the surface of the subgrade and the muddy and weak subgrade;

[0041] Step 2: Lay a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion, make a 4% drainage slope, and lay a single-line laying width of 5 meters, 2.5 meters on both sides of the line center; the double-line laying width is half the line spacing width + 2.5 meters;

[0042] Step 3: Lay a 2mm thick and ≥1m wide modified nano-gelling agent cured coating anti-seepage patch, with the patch overlap not less than 5cm;

[0043] Step 4, repeat step S2 and step S3, and adjust the thickness in step 3 to 3 mm;

[0044] Step 5: Spread 3-5cm of surface sand and level it with a sand scraper;

[0045] Step 6: paving ballast, raising the track, repairing and restoring the line;

[0046] Step 7: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is rainfall flooding the roadbed, deepen and widen the drainage side ditches. Deepen the side ditches in groundwater road cuttings and set up water collection wells in the side ditches when necessary.

[0047] The present invention has the following beneficial effects:

[0048] The present invention classifies the severity of mud and oozing according to the geological characteristics, mineral composition and rainfall characteristics of the on-site roadbed rock and soil, and designs various combinations of natural rock asphalt and nano-modified nano-gelling agent consolidation layer and nano-gelling agent cured coating anti-seepage patch, so as to give full play to the engineering characteristics and anti-seepage characteristics of the nano-gelling agent consolidation material, quickly form a tough waterproof layer with a certain strength, effectively prevent and control the formation and development of mud and oozing diseases, save engineering costs to the greatest extent, and shorten construction time.

[0049] Research has found that the high-pressure spray consolidation layer of ordinary asphalt-based binders that have not been fully rolled still has defects in impermeability, anti-aging, anti-rheology, anti-shear and overall long-term strength under the long-term linear dynamic load of trains. The present invention uses newly developed natural rock asphalt and nano-modified nano-gelling agent as consolidating materials. The material is a common gelling agent mixed with three modifiers, rock asphalt, graphene and nano-calcium, which overcomes the shortcomings of the long-term mechanical effect of the track of ordinary gel consolidation.

[0050] Natural rock asphalt is formed by long-term geological action, with large molecular weight and strong activity. The functional groups formed by its nitrogen, oxygen, sulfur and other elements are generally higher than those of matrix asphalt. Its high strength, anti-aging, durability, good compatibility with matrix asphalt and anti-peeling properties can greatly improve the initial strength and durability of mixed cementitious materials. Nanocarbon materials (graphene) have the characteristics of high strength, high toughness, large specific surface area of ​​flaky particles and high surface activity; nano calcium has high strength and anti-aging, reduces the microscopic voids in the consolidation layer, and improves the uniformity and anti-aging properties of the strength of the consolidation object; certain carbonized rock asphalt has good compatibility with ordinary gel asphalt matrix, which not only significantly enhances the dynamic shear modulus of the matrix asphalt, reduces the phase angle, and improves the high temperature deformation resistance, but also the microstructure of the porous rock asphalt carbon material after partial carbonization is mainly mesopores, with a large specific surface area, which can well adsorb the flaky nano graphene and high-strength nano calcium around the carbonized rock asphalt particles or in the mesopores to form a tight combination and block the microstructure channel of the seepage water. The three modifiers work together with rock asphalt as a link to improve the overall structure of the mixture, enhance the connection area and adhesion strength of the cementitious material and crushed stone (stone chips) particles, strengthen the overall impermeability of the consolidated layer and its ability to resist creep and aging under long-term linear vibration loads, and improve the long-term effectiveness, density and shear strength of the consolidated layer.

[0051] The present invention adopts various combinations of new natural rock asphalt and nano-modified nano-gelling agent consolidation products and natural rock asphalt and nano-modified nano-gelling agent cured coating anti-seepage patches. Aiming at the different degrees of roadbed diseases, the present invention adopts three methods for constructing the anti-seepage protective layer on the surface of the subgrade. On the premise of strengthening the drainage of the roadbed and on the basis of improving the overall strength of the surface of the roadbed subgrade, it effectively prevents the infiltration of atmospheric precipitation, blocks the hydraulic connection between atmospheric precipitation and the hydrophilic minerals of the rock and soil on the surface of the roadbed subgrade, and cures the disease from the source of the mud and slurry disease of the roadbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is the calculation flow chart;

[0053] Figure 2 It is the numerical calculation model of roadbed;

[0054] Figure 3 This is the technical solution diagram for the treatment of mud and slurry.

[0055] Figure 4 Set up a schematic diagram for the monitoring points;

[0056] Figure 5 It is the vertical stress variation diagram of the monitoring point;

[0057] Figure 6 This is the pore water pressure change diagram. DETAILED DESCRIPTION

[0058] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] like Figure 1 As shown, a method for treating mud bubbling in ballasted railway expansive rock soil roadbed of the present invention comprises the following steps:

[0060] A method for treating mud bubbling in ballasted railway expansive rock soil roadbed of the present invention comprises the following steps:

[0061] Step S1, conducting a survey and sampling test on the rock and soil characteristics and main clay mineral components of the roadbed: focusing on the geological origin, age, material composition, clay content, clay mineral type and content of the bed material, and taking samples for relevant geotechnical tests and mineral composition and content tests, and classifying the expansion potential of the bed soil according to Table 1 based on the clay composition and content test data;

[0062] Table 1 Swelling potential classification

[0063]

[0064] Step S2, investigating the annual precipitation in the railway mud-swelling area and calculating the average annual precipitation;

[0065] Step S3, investigating the degree of mud overflow on the roadbed, and determining the basic characteristics of mud overflow by statistical analysis: the number of continuous sleepers with mud overflow, the height of the mud overflow reaching the upper ballast, the degree of mud pollution on the surface ballast, and the number and location of mud splashing points;

[0066] Step S4, investigating the roadbed drainage conditions, focusing on investigating the side ditch depth, width, blockage and catchment area of ​​the road cutting section, and determining the degree of drainage blockage;

[0067] Step S5, investigating the rail surface wear, direction, height change and triangular pits to determine the rail status;

[0068] Step S6, assigning values ​​to the above parameters and calculating them, and classifying the mud-swelling diseases according to the calculation results;

[0069] Step S61, determining a first rating factor, a second rating factor, a third rating factor, a fourth rating factor, a fifth rating factor, a sixth rating factor, a seventh rating factor, an eighth rating factor, and a ninth rating factor according to the expansion potential of the subgrade soil, the cause of the subgrade soil, the type of mud overflow, the average annual precipitation, the basic characteristics of mud overflow, the degree of drainage blockage, and the state of the rails;

[0070] When the expansion potential of the subgrade soil is weak, medium, and strong, the first rating factor M1 is 30, 60, and 100 respectively;

[0071] When the bed soil is formed by slope alluvial, flood alluvial, and lake deposits, the second rating factor M2 is 10, 20, and 30 respectively;

[0072] When the mud-overturning types are mudstone bed, soil bed, mudstone clay bed, the third rating factor M3 is 20, 30, 40 respectively;

[0073] When the average annual precipitation R is R≤400mm, 400mm <R≤800mm、800mm<R≤1600mm、R> At 1600mm, the fourth rating factor M4 is: 10, 20, 40, 60;

[0074] When the positions of the slurry in the basic characteristics of slurry are: a small amount of slurry to the bottom of the pillow, a large amount of slurry to the bottom of the pillow and a small amount to the pillow surface, and a large amount of slurry to the pillow surface, the fifth rating factor M5 is 40, 60, and 100 respectively;

[0075] When the slurry season is n months, the sixth rating factor M6=3n;

[0076] When the continuous length of the slurry is Lm, the seventh rating factor M7=3 L1 / 2, if M7 is greater than 30, take M7=30;

[0077] When the rail surface wear is slight, the change of rail direction is slight, and the change of rail surface height is slight, the eighth rating factor M8=10; when the rail surface wear is moderate, the change of rail direction is small, and the change of rail surface height is small, the eighth rating factor M8=20; when the rail surface wear is severe, the change of rail direction is large, and the change of rail surface height is a triangular pit, the eighth rating factor M8=40;

[0078] When the drainage obstruction degree is that the side ditch and the line are unobstructed, blocked, and severely blocked, the ninth rating factor M9 is 10, 30, and 50 respectively;

[0079] Step S62: Calculate the mud boiling disease rating value M by summing up the first rating factor, the second rating factor, the third rating factor, the fourth rating factor, the fifth rating factor, the sixth rating factor, the seventh rating factor, the eighth rating factor, and the ninth rating factor. 10 ;

[0080]

[0081] Step S63: According to the mud oozing disease rating value M 10 To classify;

[0082] When the mud oozing disease rating value is M 10 When it is less than 160, the mud-overflowing disease is assessed as weak;

[0083] When the mud oozing disease rating value is M 10 When it is greater than or equal to 160 and less than 280, the mud and mud disease is rated as medium;

[0084] When the mud oozing disease rating value is M 10 When it is greater than or equal to 280, the mud and slurry disease is assessed as severe;

[0085] Step S7, determining the corresponding protective layer combination thickness and specific treatment plan according to the mud overflow disease level;

[0086] When the mud oozing disease is assessed as weak, a 3cm thick consolidation layer of modified nano gelling agent and washed stone chips mixed in the best proportion is constructed on the surface of the roadbed. A 3mm thick modified nano gelling agent cured coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer with a certain strength. The anti-seepage patch is spread with no less than 3cm of medium-coarse sand. The consolidation layer, tough waterproof layer and medium-coarse sand form a three-layer protective layer structure. The strength of the consolidation layer reaches more than 50KPa within 5-10 minutes.

[0087] like Figure 3 As shown in the figure, when the mud oozing disease is assessed as weak, the specific treatment plan steps are as follows:

[0088] Step 1: Use a 60, 70, or 80-type small excavator to clean and dig out the ballast, mud on the surface of the subgrade, and the muddy and weak subgrade. The depth should be controlled to be no less than 35 cm at the bottom of the sleeper. When the moisture content is greater than 25%, spread silica cement and tamp the subgrade surface.

[0089] Step 2: Lay a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips in the best mix ratio, make a 4% drainage slope, and lay a single-line width of 5 meters, 2.5 meters on both sides of the line center; the double-line laying width is half the width of the line spacing + 2.5 meters; when the consolidation layer construction process is available, use on-site mixing, paving and rolling to build the consolidation layer. When the working conditions are not met, use the online pulling and moving pillows to form a continuous moving working surface, and the external spraying equipment of the roadbed slope foot uses high-pressure solid-liquid distribution and automatic mixing and spraying technology at the nozzle to build the consolidation layer;

[0090] Step 3: Lay a modified nano-gelling agent cured coating anti-seepage patch with a thickness of 3 mm and a width of ≥ 1 m, with the patch overlap not less than 5 cm;

[0091] Step 4: Spread 3-5cm of surface sand and level it with a sand scraper;

[0092] Step 5: paving ballast, raising the track, repairing and restoring the line;

[0093] Step 6: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is precipitation flooding the roadbed, deepen and widen the drainage side ditches; deepen the side ditches in the groundwater road cutting, and set up water collection wells in the side ditches when necessary;

[0094] When the mud oozing disease is assessed as medium, a 6cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion is constructed on the surface of the roadbed, and a 3mm thick modified nano-gelling agent cured coating anti-seepage patch is laid on the consolidation layer; a tough waterproof layer with a certain strength is quickly formed, and the anti-seepage patch is spread with medium-coarse sand of not less than 3cm, wherein the consolidation layer, tough waterproof layer and medium-coarse sand form a three-layer protective layer structure, and the strength of the consolidation layer reaches more than 50KPa within 5-10 minutes;

[0095] When the mud and slurry disease is assessed as medium, the specific treatment plan steps are as follows:

[0096] Step 1: Use a 60, 70, or 80-type small excavator to clean and dig out the ballast, mud on the surface of the subgrade, and the muddy and weak subgrade. The depth should be controlled to be no less than 35 cm at the bottom of the sleeper. When the moisture content is greater than 25%, spread silica cement and tamp the subgrade surface.

[0097] Step 2: Lay a 6cm thick consolidation layer of modified nano-gelling agent and washed stone chips in the best mix ratio, make a 4% drainage slope, and lay a single-line width of 5 meters, 2.5 meters on both sides of the line center; the double-line laying width is half the width of the line spacing + 2.5 meters; when the consolidation layer construction process is available, use on-site mixing, paving and rolling to build the consolidation layer. When the working conditions are not met, use the online pulling and moving pillows to form a continuous moving working surface, and the external spraying equipment of the roadbed slope foot uses high-pressure solid-liquid distribution and automatic mixing and spraying technology at the nozzle to build the consolidation layer;

[0098] Step 3: Lay a modified nano-gelling agent cured coating anti-seepage patch with a thickness of 3 mm and a width of ≥ 1 m, with the patch overlap not less than 5 cm;

[0099] Step 4: Spread 3-5cm of surface sand and level it with a sand scraper;

[0100] Step 5: paving ballast, raising the track, repairing and restoring the line;

[0101] Step 6: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is precipitation flooding the roadbed, deepen and widen the drainage side ditches; deepen the side ditches in the groundwater road cutting, and set up water collection wells in the side ditches when necessary;

[0102] When the mud oozing disease is assessed as serious, a 3cm thick consolidation layer of modified nano gelling agent and washed stone chips mixed in the best mix ratio is constructed on the surface of the roadbed, and a 2mm thick modified nano gelling agent solidified coating anti-seepage patch is laid on the consolidation layer. A 3cm thick consolidation layer of modified nano gelling agent and washed stone chips mixed in the best mix ratio is constructed on the anti-seepage patch, and a 3mm thick modified nano gelling agent solidified coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer with a certain strength. The anti-seepage patch is paved with no less than 3cm of medium-coarse sand, wherein the consolidation layer, modified nano gelling agent solidified coating anti-seepage patch, consolidation layer, tough waterproof layer, and medium-coarse sand form a five-layer protective layer structure, and the strength of the consolidation layer reaches more than 50KPa within 5-10 minutes;

[0103] When the mud and slurry disease is assessed as serious, the specific treatment plan steps are as follows:

[0104] Step 1: Use a 60, 70, or 80-type small excavator to clean and dig out the ballast, mud on the surface of the subgrade, and the muddy and weak subgrade. The depth should be controlled to be no less than 35 cm at the bottom of the sleeper. When the moisture content is greater than 25%, spread silica cement and tamp the subgrade surface.

[0105] Step 2: Lay a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips in the best mix ratio, make a 4% drainage slope, and lay a single-line width of 5 meters, 2.5 meters on both sides of the line center; the double-line laying width is half the width of the line spacing + 2.5 meters; when the consolidation layer construction process is available, use on-site mixing, paving and rolling to build the consolidation layer. When the working conditions are not met, use the online pulling and moving pillows to form a continuous moving working surface, and the external spraying equipment of the roadbed slope foot uses high-pressure solid-liquid distribution and automatic mixing and spraying technology at the nozzle to build the consolidation layer;

[0106] Step 3: Lay a 2mm thick and ≥1m wide modified nano-gelling agent cured coating anti-seepage patch, with the patch overlap not less than 5cm;

[0107] Step 4, repeat step S2 and step S3, and adjust the thickness in step 3 to 3 mm;

[0108] Step 5: Spread 3-5cm of surface sand and level it with a sand scraper;

[0109] Step 6: paving ballast, raising the track, repairing and restoring the line;

[0110] Step 7: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is rainfall flooding the roadbed, deepen and widen the drainage side ditches. Deepen the side ditches in groundwater road cuttings and set up water collection wells in the side ditches when necessary.

[0111] In the present invention, the position and thickness of the protective layer are optimized and designed, and the specific process is as follows: Figure 1 As shown,

[0112] (1) Set calculation parameters. According to different roadbed soil layers, set the elastic modulus, Poisson's ratio, porosity, saturation, permeability coefficient and other calculation parameters of each soil layer;

[0113] Principles of parameter selection: soil layer type and depth distribution data can be obtained from design data. The calculation of physical and mechanical parameters should be obtained by drilling sampling test. A certain depth (determine the drilling depth according to the specific terrain conditions on site, but the depth must exceed 1m of the roadbed disease layer) is designed in the project area. The sampling interval is 1m, and the number is not less than 5 standard samples. The calculation parameters such as the natural density, moisture content, specific gravity, porosity, saturation, deformation modulus, Poisson's ratio, and permeability coefficient of the soil layer are obtained through indoor testing. Each parameter test has no less than 4 valid data, and the average value is selected and substituted into the calculation model.

[0114] (2) Discrete cells: According to the specific geometric characteristics of the roadbed and the calculation accuracy requirements, set the appropriate cell size and discrete calculation model, such as Figure 2 As shown;

[0115] General principles for cell setting: the size of cells in the roadbed soil layer shall not exceed 0.2m, and the size of cells in the track stress area shall not be larger than 0.1m. The design treatment layer can be appropriately encrypted, and the specific size is determined through trial calculation to ensure that the calculation accuracy can be achieved.

[0116] (3) Setting the boundary conditions and initial conditions of the numerical model, with the boundary set as an impermeable layer;

[0117] Setting principle: The bottom and sides of the model are set as normal displacement constraints, and the track and roadbed surface are set as free boundaries. The rock and soil are initially set to be in a saturated state.

[0118] (4) If Figure 4 As shown, calculation monitoring points of different depths are set under the roadbed, and the strain, vibration velocity, and excess pore water pressure data of the monitoring points are recorded during the calculation process;

[0119] Principles for setting up monitoring points: Groundwater pressure monitoring points are set from the bottom of the cross-section track with an interval of 0.5m. The setting depth is determined by the location of the diseased layer detected by drilling, and in principle, it should be 0.5m higher than the diseased layer.

[0120] (5) If Figure 5 As shown, gravity load and train dynamic load are applied and the finite difference calculation program is used for calculation;

[0121] The train vibration load and its frequency should be determined through on-site measurements or track design load data. A vibration load sensor is set at the bottom of the track to collect the vibration load and vibration frequency when the train passes, and the collected data is filtered and applied to the calculation model.

[0122] (6) Figure 6 As shown, the finite difference calculation program is used to calculate and draw the monitoring variable curve of the monitoring point.

[0123] After applying vibration load on the rail surface, the changes in excess pore water pressure in the rock and soil layer were monitored during the calculation process.

[0124] (7) According to the distribution of pore water pressure, set the position, depth and thickness of the base bed closed protective layer. Set the protective layer in the model according to the design data, repeat the calculation process of steps (1) to (5), and verify the protective effect of the protective layer. According to the calculation results, optimize the position and thickness of the protective layer.

[0125] The above description is not intended to limit the present invention in any form. Although the present invention has been disclosed through the above embodiments, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A method for treating mud and slurry in ballasted railway expansive rock soil roadbed, characterized in that: The following steps are involved: Step S1, conducting a survey and sampling test on the rock and soil characteristics of the roadbed and the main clay mineral components, and taking samples for relevant geotechnical tests and mineral composition and content tests, and classifying the expansion potential of the subgrade soil according to the clay composition and content test data; Step S2, investigating the annual precipitation in the railway mud-swelling area and calculating the average annual precipitation; Step S3, investigating the degree of mud slurry on the roadbed, and determining the basic characteristics of mud slurry by statistical analysis; Step S4, investigating the roadbed drainage situation and determining the degree of drainage blockage; Step S5, investigating the rail surface wear, direction, height change and triangular pits to determine the rail status; Step S6, assigning values ​​to the above parameters and calculating them, and classifying the mud-swelling diseases according to the calculation results; Step S61, determining a first rating factor, a second rating factor, a third rating factor, a fourth rating factor, a fifth rating factor, a sixth rating factor, a seventh rating factor, an eighth rating factor, and a ninth rating factor according to the expansion potential of the subgrade soil, the cause of the subgrade soil, the type of mud overflow, the average annual precipitation, the basic characteristics of mud overflow, the degree of drainage blockage, and the state of the rails; Step S62: Calculate the mud boiling disease rating value M by summing up the first rating factor, the second rating factor, the third rating factor, the fourth rating factor, the fifth rating factor, the sixth rating factor, the seventh rating factor, the eighth rating factor, and the ninth rating factor. 10 ; Step S63: According to the mud oozing disease rating value M 10 To classify; When the mud oozing disease rating value is M 10 When it is less than 160, the mud-overflowing disease is assessed as weak; When the mud oozing disease rating value is M 10 When it is greater than or equal to 160 and less than 280, the mud and mud disease is rated as medium; When the mud oozing disease rating value is M 10 When it is greater than or equal to 280, the mud and slurry disease is assessed as severe; Step S7, determining the corresponding protective layer combination thickness and specific treatment plan according to the mud overflow disease level; When the mud swell disease is assessed as weak, a 3cm thick consolidation layer of modified nano gelling agent and washed stone chips mixed in the best proportion is constructed on the surface of the roadbed. A 3mm thick modified nano gelling agent cured coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer. Medium-coarse sand of not less than 3cm is laid on the anti-seepage patch. The strength of the consolidation layer reaches more than 50KPa within 5-10 minutes. When the mud oozing disease is assessed as medium, a 6cm thick consolidation layer of modified nano gelling agent and washed stone chips mixed in the best proportion is constructed on the surface of the roadbed. A 3mm thick modified nano gelling agent cured coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer. Medium-coarse sand of not less than 3cm is laid on the anti-seepage patch. The strength of the consolidation layer reaches more than 50KPa within 5-10 minutes. When the mud and slurry disease is assessed to be serious, a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion is constructed on the surface of the roadbed. A 2mm thick modified nano-gelling agent cured coating anti-seepage patch is laid on the consolidation layer. A 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion is constructed on the anti-seepage patch. A 3mm thick modified nano-gelling agent cured coating anti-seepage patch is laid on the consolidation layer to quickly form a tough waterproof layer. The anti-seepage patch is spread with no less than 3cm of medium-coarse sand, and the strength of the consolidation layer reaches more than 50KPa within 5-10 minutes.

2. The method for treating mud bubbling in ballasted railway expansive rock soil roadbed according to claim 1, characterized in that: The expansion potential of the base soil in step S1 includes weak expansion, medium expansion and strong expansion.

3. The method for treating mud bubbling in ballasted railway expansive rock soil roadbed according to claim 2, characterized in that: The weak expansion refers to slope residual and slope diluvial rock and soil with a free expansion rate of 40 ≤Fs<60, a montmorillonite content of 7≤M<17, and a cation exchange capacity of 170≤CEC<260; the medium expansion refers to alluvial and diluvial rock and soil with a free expansion rate of 60≤Fs<90, a montmorillonite content of 17≤Fs<27, and a cation exchange capacity of 260≤CEC<360; the strong expansion refers to lacustrine rock and soil with a free expansion rate of Fs≥90, a montmorillonite content of M≥27, and a cation exchange capacity of CEC≥360.

4. The method for treating mud bubbling in ballasted railway expansive rock soil roadbed according to claim 1, characterized in that: In step S7, when the mud oozing disease is assessed as weak, the corresponding specific treatment plan is: Step 1: clean and remove the ballast, mud on the surface of the subgrade and the muddy and weak subgrade; Step 2: Lay a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion, make a 4% drainage slope, and lay a single-line laying width of 5 meters, 2.5 meters on both sides of the line center; the double-line laying width is half the line spacing width + 2.5 meters; Step 3: Lay a modified nano-gelling agent cured coating anti-seepage patch with a thickness of 3 mm and a width of ≥ 1 m, with the patch overlap not less than 5 cm; Step 4: Spread 3-5cm of surface sand and level it with a sand scraper; Step 5: paving ballast, raising the track, repairing and restoring the line; Step 6: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is rainfall flooding the roadbed, deepen and widen the drainage side ditches. For groundwater road cuttings, deepen the side ditches and set up water collection wells in the side ditches.

5. The method for treating mud bubbling in ballasted railway expansive rock soil roadbed according to claim 1, characterized in that: In step S7, when the mud oozing disease is assessed as medium, the corresponding specific treatment plan is: Step 1: clean and remove the ballast, mud on the surface of the subgrade and the muddy and weak subgrade; Step 2: Lay a 6cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion, make a 4% drainage slope, and lay a single-line 5m wide, 2.5m on each side of the line center; double-line laying width is half the line spacing width + 2.5m; Step 3: Lay a modified nano-gelling agent cured coating anti-seepage patch with a thickness of 3 mm and a width of ≥ 1 m, with the patch overlap not less than 5 cm; Step 4: Spread 3-5cm of surface sand and level it with a sand scraper; Step 5: paving ballast, raising the track, repairing and restoring the line; Step 6: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is rainfall flooding the roadbed, deepen and widen the drainage side ditches. For groundwater road cuttings, deepen the side ditches and set up water collection wells in the side ditches.

6. The method for treating mud bubbling in ballasted railway expansive rock soil roadbed according to claim 1, characterized in that: In step S7, when the mud boiling disease is assessed as serious, the corresponding specific treatment plan is: Step 1: clean and remove the ballast, mud on the surface of the subgrade and the muddy and weak subgrade; Step 2: Lay a 3cm thick consolidation layer of modified nano-gelling agent and washed stone chips mixed in the best proportion, make a 4% drainage slope, and lay a single-line laying width of 5 meters, 2.5 meters on both sides of the line center; the double-line laying width is half the line spacing width + 2.5 meters; Step 3: Lay a 2mm thick and ≥1m wide modified nano-gelling agent cured coating anti-seepage patch, with the patch overlap not less than 5cm; Step 4, repeat step S2 and step S3, and adjust the thickness in step 3 to 3 mm; Step 5: Spread 3-5cm of surface sand and level it with a sand scraper; Step 6: paving ballast, raising the track, repairing and restoring the line; Step 7: Clean the side ditches in the road cutting section to prevent water accumulation in the side ditches. If the catchment area is large and there is rainfall flooding the roadbed, deepen and widen the drainage side ditches. For groundwater road cuttings, deepen the side ditches and set up water collection wells in the side ditches.

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