WO2011079676A1 - Construction method for supporting layer of double-block ballastless track - Google Patents

Abstract

A construction method for a supporting layer of a double-block ballastless track comprises the following steps first, measuring and laying off datum lines, second, preparing mixture, third, producing and transporting mixture, forth, paving the mixture to form the supporting layer, fifth, checking appearance quality, sixth, manually deburring the supporting layer, seventh, cutting joints and curing the supporting layer, eighth, testing and evaluating the supporting layer.

Description

 TECHNICAL FIELD The present invention relates to the construction process of a high-speed railway passenger dedicated line, and particularly relates to a double-block ballastless track formed by using a slipform paver to spread a hydraulic mixture in a railway. Support layer construction process. BACKGROUND OF THE INVENTION A ballastless track support layer is an intermediate transition layer between the bed of a ballastless track and the surface of a subgrade bed, and is a key process in the construction of a double block ballastless track bed. In foreign countries, when Germany began the ballastless track test study, a concrete support layer structure was set up between the roadbed bed surface and the track bed plate with reference to the road structure design. With the expansion of the application range of ballastless track, the process has also evolved from the original rolling type to the current slipform paving. Slip mode paving technology is a cement concrete pavement forming technology that is widely promoted and used in the construction of highways and airports in China. It is not widely used in railways. It is mainly used in track-slip mode cement concrete pavers. The paving materials mainly include ordinary concrete. Due to the existence of concrete: 1 the concrete strength is higher; 2 the water consumption is larger, the concrete slump is larger; 3 the cementing material is more. On the one hand, the occurrence of these conditions leads to an increase in the shrinkage of the support layer, on the one hand, the rigidity of the support layer is too large, and the ability to release stress is weakened, thereby accelerating the tendency of the bed plate to crack. In order to improve the construction quality of the support layer, reduce the probability of cracking of the ballast plate, and increase the durability of the structure, a construction process using a support layer material as a hydraulic mixture and a slipform paver molding technique is considered to solve the above problems. The preferred method. Summary of the invention

The object of the invention is to provide a double-block ballastless track supporting layer construction technology, which has the characteristics of high construction speed and large operation efficiency of the paver, can improve the construction quality of the support layer and reduce The probability of cracking the bed plate and increasing the durability of the structure.

 A double-block ballastless track supporting layer construction process, which comprises the following steps:

 A double-block ballastless track supporting layer construction process, characterized in that it comprises the following steps: First step, reference line setting

 Before the construction, the measurement and release work of the support layer is completed, and the center line of the concrete support layer is set by the CPIII control network, and the guide lines on both sides are set, and the distance from the guide line to the line center line is 2. 9 meters, and the height is designed to cover the road surface 50. Cm, the longitudinal distance of the guide line tie rod is 10 meters, and the curved section is 5 meters; the paving uses the nail pile or guide line method to calibrate the pitch of the four corners of the bottom of the paver and the direction of the side mold, check 1~2 times, correct After the error, the paving operation is carried out;

 The second step, the mixture preparation

 A. According to the recommended mixing ratio of the laboratory, carry out the process test on site, comprehensively analyze the compactness and compressive strength index of the support layer, the workability of the mixed material, the work performance, the appearance quality factor, and modify the mix ratio of the support layer;

 B. Sampling the material at the site, performing the aggregate screening test to check the aggregate gradation; measuring the moisture content of the sand and stone at the mixing station, adjusting the theoretical mix ratio according to the water content, determining the construction mix ratio, mixing After the mixing of the materials is completed, the water content is measured by sampling;

 C. The determined raw material weight ratio is: cement, mineral admixture 1%, coarse and fine aggregate ratio 2%, mixing water ratio 1%;

 D. The mixing process of the support layer mixture is as follows:

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E. The support layer mixture is thoroughly stirred, so that the various materials are uniformly mixed and the colors are the same. Transport to the construction site for use;

 The third step, mixed material transportation

 Before the transportation, the self-unloading automobile car is cleaned and covered with canvas during the transportation process of the support layer mixture by the self-unloading automobile. After the mixed material is transported to the construction site, the discharge distance is not limited to the evaporation of water;

 The fourth step, the support layer mix paving

 First, sprinkle the surface of the surface of the bed before weaving;

 Then, the mixture is transported to the construction site for sampling, and the water content is measured;

 Finally, during paving, the support layer mixture is finished by the excavator: the fabric is evenly distributed within the width of the paving, and the highest level is not higher than the normal height of the top surface of the loose control panel of the paver, while in the auger Below the highest point of the blade, and not to be short of material; after the longitudinal fabric exceeds 5 meters, the paver starts to spread. When the fabric is in the curved section, the outer fabric height is slightly higher, and it is determined within the paving distance of 5 to 10 meters. Optimal vibrating frequency, optimum paving speed and optimum insertion depth of the tamping rod;

 Step 5, appearance quality check

 After the paving is completed, the quality of the support layer is checked. The main contents of the inspection include: Observing whether the support layer is isolated, if it is repaired immediately; and checking the surface elevation of the support layer, pulling the string between the two reference lines, Use a steel ruler to measure the distance from the string to the surface of the support layer. If the elevation exceeds the allowable error, handle it immediately;

 Step 6, manual trimming

 The subgrade support layer is dry hard concrete, and the surface of the support layer has a certain roughness in the range of the track bed, so that it can be in good contact with the interface of the track bed. The exposed part of the edge of 35 cm on both sides should be manually covered and smeared to avoid excessive holes. Excessive water absorption causes freezing and thawing damage;

The seventh step, the support layer slitting, maintenance: Within 12 hours after the support layer is paved, the transverse joint is cut at a pitch of 5 meters in the longitudinal direction. The seam depth is 1/3 of the thickness of the concrete of the support layer. After the slitting work is completed, the surface of the support layer is sprinkled with water and covered with plastic film for 5 days. ;

 The eighth step, detection, evaluation:

 After the completion of the construction, the compactness of the support layer mixture shall be determined by sand blasting every 500 meters. The core shall be sampled every 250 meters. The diameter of the core sample is 150 mm. The compressive strength test shall be carried out to determine the 28-day support layer mixture. The strength of the support layer is evaluated after the test data is completed.

 Due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

 It has the characteristics of fast construction speed and high efficiency of paver operation, which can reach the construction progress of 300m/day, which can greatly reduce the construction period; it can improve the construction quality of the support layer, reduce the cracking probability of the track bed and increase the durability of the structure.

DRAWINGS

 Figure 1 is a flow chart of the construction process of the double-block ballastless track support layer.

 Figure 2 is a gradation plot of a mixture of mineral materials. detailed description

 The present invention will be described in detail below with reference to the accompanying drawings.

 1. Support layer matching ratio test

 1. 1 trial matching principle

 After the entrance test of the concrete of the supporting layer is qualified, the compounding test should be carried out in advance according to the requirements of the “temporary technical conditions for the ballastless track support layer of the passenger dedicated railway line” and the actual indicators such as cement and aggregate at the construction site. .

1. 2 indoor test

1. 2. 1 screening According to JGJ52-2006, the standard for sand and stone quality and test methods for ordinary concrete, the coarse and fine aggregates are first sieved separately, and then the two aggregates are tested and sieved according to a certain ratio until the sieve The scores meet the particle size grading of the mixture in the Interim Technical Conditions (see Table 1. 2. 1) and the grading curve limits (see Figure 2), and plot the graph.

 Table 1. 2. 1 particle size grading of the mixture

 1. 2. 2 compaction

 The two aggregates were mixed according to the test ratio, and cement and fly ash were added, and the compaction test was carried out by a compactor to obtain the maximum dry density and the optimum moisture content.

 1. 2. 3 mixed type

 Calculate the theoretical mix ratio according to the obtained maximum dry density and optimum water content (see Table 1.2.3) and mix the test materials of various materials into the mixer for mixing, and then compact the test pieces according to the regulations. After 1 day, it was demolded and placed in a standard curing room for curing.

Table 1. 2. Theoretical support ratio of support layer (kg/m3)

 1. 2. 4 performance test

 The specimens for curing 3d, 7d, and 28d were subjected to mechanical (compression) performance tests. The test results are shown in Table 1. 2. 4.

Table 1. 2. 4 Test results of mechanical properties of support layer Requires laboratory to achieve compressive strength (MPa)

 To intensity (Mpa) 3d 7d 28d

 ^ 15 130 9.7 13.3 19.2

 150 10.1 14.6 20.1

 1. 3 process test and mix correction

 1.3.1 Verifying the mixing ratio of the laboratory According to the recommended ratio of the laboratory, carry out the process test on site, actually pave the test section, and test the dry density and compressive strength; and compare with the provisions of the Provisional Technical Conditions. The value is verified. The test results are shown in Table 1. 3. 1-1, Table 1. 3. 1-2

 Table 1. 3. 1-1 Sanding method compactness test results

Table 1. 3. 1-2 Strength test results

1. 3. 2 Correct the support layer mix ratio to summarize the results of the process test, comprehensively analyze the compactness and strength index of the support layer, the workability of the mix, work performance, appearance quality and other factors, modify the mix ratio of the support layer, according to the analysis , determine the corrected support layer mix ratio. 1. 4 construction mix ratio determination

 Before each support layer is constructed, the moisture content of sand, stone and other raw materials must be tested. According to the test results of water content, the theoretical mix ratio is corrected to determine the final construction mix ratio.

 2. Construction process

 A double-block ballastless track supporting layer construction process, which comprises the following steps:

 First step, baseline measurement

 Before the construction, the measurement and release work of the support layer is completed: the center line of the concrete support layer is set by the CPIII control network, and the guide lines on both sides are set, and the distance from the guide line to the line center line is 2. 9 meters, and the height is designed to cover the road surface 50. Cm, the longitudinal distance of the guide line tie rod is 10 meters, and the curved section is 5 meters; the paving uses the nail pile or guide line method to calibrate the pitch of the four corners of the bottom of the paver and the direction of the side mold, check 1~2 times, correct After the error is correct, the paving operation can be carried out;

 The second step, the mixture preparation

 A. According to the recommended mixing ratio of the laboratory, carry out the process test on site, comprehensively analyze the compactness and compressive strength index of the support layer, the workability of the mixed material, the work performance, the appearance quality factor, and modify the mix ratio of the support layer;

 B. Sampling the material at the site, performing the aggregate screening test to check the aggregate gradation; measuring the moisture content of the sand and stone at the mixing station, adjusting the theoretical mix ratio according to the water content, determining the construction mix ratio, mixing After the mixing of the materials is completed, the water content is measured by sampling;

 C. The determined raw material weight ratio is: cement, mineral admixture 1%, coarse and fine aggregate ratio 2%, mixing water ratio 1%; feeding sequence: after the raw material is metered, first put fine aggregate into the mixer, Cement and fly ash, add water after mixing, then add coarse aggregate to the mixer, stir well until it is even;

D. The mixing process of the support layer mixture is as follows: 细ΐ录1 #合水耜骨肢: » #抖

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 Ε. The support layer mixture is fully stirred, so that the various materials are evenly mixed and the colors are consistent, and the mixture is transported to the construction site for use;

 The third step, mixed material transportation

 Before the transportation, the self-unloading automobile car is cleaned and covered with canvas during the transportation process of the support layer mixture by the self-unloading automobile. After the mixed material is transported to the construction site, the discharge distance is not limited to the evaporation of water;

 The fourth step, the support layer mix paving

 First, sprinkle the surface of the surface of the bed before weaving;

 Then, the mixture is transported to the construction site for sampling, and the water content is measured;

 Finally, during paving, the support layer mixture is finished by the excavator: the fabric is evenly distributed within the width of the paving, and the highest level is not higher than the normal height of the top surface of the loose control panel of the paver, while in the auger Below the highest point of the blade, and not to be short of material; after the longitudinal fabric exceeds 5 meters, the paver starts to spread, and when the fabric is in the curved section, the outer fabric height is slightly higher, so that the paving can be paved during the paving process. The machine template forms an extrusion on the mixture to ensure the quality effect of the support layer; determine the optimal vibration frequency, the optimum paving speed and the optimal insertion depth of the tamping rod within a paving distance of 5 to 10 meters;

 The fifth step, the appearance quality check:

After the paving is completed, the quality of the support layer is checked. The main contents of the inspection include: Observing whether the support layer is isolated, if it is repaired immediately; Checking the surface elevation of the support layer and pulling the string between the two baselines , using a steel ruler to measure the distance from the string to the surface of the support layer, if the elevation exceeds the error The difference is allowed, and it is processed immediately;

 The sixth step, manual trimming:

 The subgrade support layer is dry hard concrete, and the surface of the support layer has a certain roughness in the range of the track bed, so that it can be in good contact with the interface of the track bed. The exposed part of the edge of 35 cm on both sides should be manually covered and smeared to avoid excessive holes. Excessive water absorption causes freezing and thawing damage;

 The seventh step, the support layer slitting, maintenance:

 Within 12 hours after the support layer is paved, the transverse joint is cut at a pitch of 5 meters in the longitudinal direction. The seam depth is 1/3 of the thickness of the concrete of the support layer. After the slitting work is completed, the surface of the support layer is sprinkled with water and covered with plastic film for 5 days. ;

 The eighth step, detection, evaluation:

 After the completion of the construction, the compactness of the support layer mixture shall be determined by sand blasting every 500 meters. The core shall be sampled every 250 meters. The diameter of the core sample is 150 mm. The compressive strength test shall be carried out to determine the 28-day support layer mixture. The strength of the support layer is evaluated after the test data is completed.

 The invention has the characteristics of high construction speed and large operation efficiency of the paver, can reach the construction progress of 300 m/day, and can greatly reduce the construction period; can improve the construction quality of the support layer, reduce the cracking probability of the road bed plate and increase the durability of the structure. .

Claims

Claim

A double-block ballastless track supporting layer construction process, characterized in that it comprises the following steps: First step, reference line setting

 Before the construction, the measurement and release work of the support layer is completed, and the center line of the concrete support layer is set by the CPIII control network, and the guide lines on both sides are set, and the distance from the guide line to the line center line is 2. 9 meters, and the height is designed to cover the road surface 50. Cm, the longitudinal distance of the guide line tie rod is 10 meters, and the curved section is 5 meters; the paving uses the nail pile or guide line method to calibrate the pitch of the four corners of the bottom of the paver and the direction of the side mold, check 1~2 times, correct After the error, the paving operation is carried out;

 The second step, the mixture preparation

 A. According to the recommended mixing ratio of the laboratory, carry out the process test on site, comprehensively analyze the compactness and compressive strength index of the support layer, the workability of the mixed material, the work performance, the appearance quality factor, and modify the mix ratio of the support layer;

 B. Sampling the material at the site, performing the aggregate screening test to check the aggregate gradation; measuring the moisture content of the sand and stone at the mixing station, adjusting the theoretical mix ratio according to the water content, determining the construction mix ratio, mixing After the mixing of the materials is completed, the water content is measured by sampling;

 C. The determined raw material weight ratio is: cement, mineral admixture 1%, coarse and fine aggregate ratio 2%, mixing water ratio 1%;

D. The mixing process of the support layer mixture is as follows:

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Ε. The support layer mixture is fully stirred, so that the various materials are evenly mixed and the colors are consistent, and the mixture is transported to the construction site for use; The third step, mixed material transportation

 Before the transportation, the self-unloading automobile car is cleaned and covered with canvas during the transportation process of the support layer mixture by the self-unloading automobile. After the mixed material is transported to the construction site, the discharge distance is not limited to the evaporation of water;

 The fourth step, the support layer mix paving

 First, sprinkle the surface of the surface of the bed before weaving;

 Then, the mixture is transported to the construction site for sampling, and the water content is measured;

 Finally, during paving, the support layer mixture is finished by the excavator: the fabric is evenly distributed within the width of the paving, and the highest level is not higher than the normal height of the top surface of the loose control panel of the paver, while in the auger Below the highest point of the blade, and not to be short of material; after the longitudinal fabric exceeds 5 meters, the paver starts to spread. When the fabric is in the curved section, the outer fabric height is slightly higher, and it is determined within the paving distance of 5 to 10 meters. Optimal vibrating frequency, optimum paving speed and optimum insertion depth of the tamping rod;

 Step 5, appearance quality check

 After the paving is completed, the quality of the support layer is checked. The main contents of the inspection include: Observing whether the support layer is isolated, if it is repaired immediately; and checking the surface elevation of the support layer, pulling the string between the two reference lines, Use a steel ruler to measure the distance from the string to the surface of the support layer. If the elevation exceeds the allowable error, handle it immediately;

 Step 6, manual trimming

 The subgrade support layer is dry hard concrete, and the surface of the support layer has a certain roughness in the range of the track bed, so that it can be in good contact with the interface of the track bed. The exposed part of the edge of 35 cm on both sides should be manually covered and smeared to avoid excessive holes. Excessive water absorption causes freezing and thawing damage;

 The seventh step, the support layer slitting, maintenance:

Within 12 hours after the support layer is paved, the transverse joint is cut at a pitch of 5 meters in the longitudinal direction, and the seam depth is supported. 1/3 of the thickness of the layer of concrete, after the completion of the slitting work, watering the surface of the support layer and covering the plastic film for 5 days;

 The eighth step, detection, evaluation:

 After the completion of the construction, the compactness of the support layer mixture shall be determined by sand blasting every 500 meters. The core shall be sampled every 250 meters. The diameter of the core sample is 150 mm. The compressive strength test shall be carried out to determine the 28-day support layer mixture. The strength of the support layer is evaluated after the test data is completed.