Provincial Highway 210 Gaorihan to Yangchang section of the highway project
（k-k
K39+240 level crossing construction
Special construction plan
K39+240 level crossing construction special construction plan.
1. Purpose of preparation.
1. Through the construction of the test section, determine the thickness of the loose paving, the type and combination of the compaction machinery, the rolling speed, and the number of rolling times that can reach the maximum dry density.
2. The slope excavation steps are done at the junction of the level crossing and the main line to ensure that the subgrade settlement does not occur at the cross-contact.
3. The embankment fill is carried out in strict accordance with the construction procedures of "three stages, four sections, and eight processes", and in the construction process, the construction machinery configuration scheme and construction parameters are optimized according to the analysis results of different construction data and test data.
2. Test content.
1. Packing test, test report, etc.;
2. The main parameters of the compaction process;
3. Loose thickness, rolling times, rolling speed;The optimal water content and the allowable deviation of the water content during rolling, etc
4. Process quality control methods and indicators;
5. Quality evaluation indicators and standards;
6. Optimized construction organization plan and process;
7. Original records.
3. Project overview.
K39 + 240 level crossing is the main line of Daliang Village must pass through, designed to facilitate the passage of local villagers, set up this crossing, but the highest part of this level crossing fill is more than 5 meters, in order to ensure the quality of subgrade construction, at the contact between the level crossing and the main line, the main line heavy bottom is dug up to the slope every 1 meter high, and the direction of the step is parallel to the main line. In order to ensure the quality of the project at the contact between the level crossing and the main road.
The criteria on which the filler is selected is based
The filler of the test section is taken from the earthwork of the southeast ditch material field. This section of soil samples in the test supervision engineer next to the station to take a representative soil sample, according to the requirements of the "highway subgrade construction technical specifications" (JTG F-2006), according to the "highway geotechnical test regulations" (JTGE40-2007) specified in the test supervision engineer next to the station under the soil sample standard compaction test, the soil sample index test results are as follows:
After the test of the above data, the soil samples can meet the packing requirements of the test section.
Preparation for construction
4.1. Machinery and equipment.
List of major facilities
4.2. Personnel composition and division of labor.
4.3. Instruments.
Measuring instruments: RTK one meter steel ruler, two 5-meter rulers, test instruments: 200 sand filling buckets.
4.4. The design traverse points were retested, encrypted and leveled points, and the original ground was retested and calculated according to the design drawings, and the K39+240 level crossing was constructed and loft.
4.5. The machinery and equipment have entered the site, the personnel have been in place, and the construction of the road has been basically completed.
Schedule
This trial section is planned to run from 17 April 2019 to 1 May 2019. In case of special weather, the site cannot be constructed, and the planned construction period will be postponed.
Construction plan and constructionCraft
Construction plan
Subgrade lofting
Before the start of the roadbed, our department first carried out the retest of the subgrade content such as the conductor, the center line, the leveling point, the cross-sectional inspection and supplementary survey, and the addition of leveling points according to the "Highway Route Survey Regulations" promulgated by the Ministry of Communications. Before the construction of the roadbed, according to the restored route in the pile, design chart, construction technology and relevant regulations, determine the subgrade land boundary pile and embankment slope foot, cutting top, side ditch and other specific position piles, and set up control piles at a certain safety distance from the center of the road, and their intervals are not more than 20m. The pile number and the height of the road center are indicated. Use (+) for fill and (-) for cut. After the side pile is placed, the slope is lofting, its elevation and width are determined, the size of the slope is controlled, and the obvious filling and excavation signs are set up at the side pile, and the pile is found to be knocked down or lost in time to make up for it in time.
Site Clearance
1. According to the requirements of the design documents, the trees and other debris within the scope of the roadbed shall be cut down or transplanted before construction, and the roots and topsoil of the turf and crops within at least 30cm below the ground shall be removed, and transported to the subgrade outside the scope of treatment or transported to the dump. After the site is cleared, the fill lot is fully rolled before filling, and the compaction degree of the roadbed reaches 90%.
2. After the site is cleaned up, it shall be reported to the supervising engineer for on-site inspection and acceptance, and the supervising engineer shall pass the acceptance before the filling can be carried out.
Fill roadbed construction
When the meter clearance is completed, dig longitudinal and horizontal drainage ditches for low-lying areas, lower the groundwater level, and dry until the requirements of rolling before filling are metDry land, dig the steps to loosen and dry and roll or replace the filling and rolling to the specification requirements, report to the supervision engineer for approval, re-release the test section of the middle and side, according to the requirements of each side of the ultra-wide 50cm.
1. When the roadbed is filled and constructed, the edge line is put first, the construction ruler is erected, and the thickness of the loose paving is cm, and the number of loose soil per car is 20m3 to calculate, and the filling area of each car of soil is calculated, and the range is drawn on the roadbed with lime to form a grid and control the spacing of each pile of filler. The construction ruler is used as the benchmark for filling height, and the thickness of the filling is controlled by the ruler rod hanging line.
During the rolling construction of the filling subgrade, the bulldozer is used to bulldoze first, and the paved soil layer that was leveled at the beginning is under the best water content (sampling by the tester), and the roller is used to press back and forth statically, and then the high-frequency, low-amplitude vibration roller is used to roll, and the rolling speed is controlled in the range of 3 6km h. For each rolling (including static pressure and vibrating rolling), the coordinates of the intersection point after rolling are randomly selected to measure its elevation, the layer thickness after rolling is calculated, and the compaction value is measured. After rolling 2 to 5 times, the best construction parameters (compaction power, rolling speed, compaction times, paving layer thickness, etc.) and mechanical combination are analyzed according to the layer thickness, the number of rolling times and the required compaction value.
Construction technology
Fill roadbed construction
1. Construction technology.
1) Measure pay-off. Based on the line center line pile, the embankment is released to fill the side pile line according to the design drawing. Sign piles are laid at the side piles to facilitate construction.
2) Substrate treatment: The embankment base is leveled and rolled before filling, so that its compaction meets the requirements of the specification.
3) Layered filling:
1) According to the laboratory, the qualified filler is determined, and the layered filling compaction is carried out. The same filler is used on the same floor to facilitate construction control. In order to ensure the width of the embankment and the compactness of the slope after compaction, each side is widened by 50cm when filling
2) Fill the embankment with soil as filler, and control its water content within the range of 2% of the optimal water content;When the lower layer of the embankment is filled, the top of the embankment is made into a 4% two-way cross slope.
4) Paving and leveling: Use a bulldozer to pave the filler according to the layer thickness of 22cm, 25cm and 30cm respectively, so as to obtain a uniform compaction effect.
5) Mechanical rolling: the straight line section is first on both sides and then **, first slow and then fast, from weak to strong, longitudinal advance and retreat. The curve section is rolled from the inside to the outside, and the longitudinal forward and backward type is rolled, and when the wheel is staggered, it overlaps 1 3 wheels wide each time. At the same time, the main wheel of the roller is in front, and the staggered wheel position is selected outside the rolling section, and it is forbidden to start quickly, brake sharply and turn around.
6) inspection visa: the whole construction process for the whole process of guidance, side station, recording, testing, the tester according to the measured compaction value after each roll to draw the rolling times and compaction degree curve;The average loosening thickness and compaction thickness, cross slope and width are measured, and the loosening coefficient is calculatedCompare the test results of three different loose paving thicknesses, select the best scheme from various perspectives such as work efficiency, equipment combination, engineering economy, etc., write a summary report of the test road and submit it to the supervision engineer for approval. The inspection should be timely and accurate, the inspection results should be complete, and the error should not exceed the specified value.
2. Quality inspection methods.
Based on the geotechnical test, the test frequency of the filler, the moisture content of the filler, the thickness of the filler, the degree of leveling, the number of rolling times, etc., are constructed, so as to achieve the purpose of both economical and effective construction and ensuring the construction quality. The quality inspection is carried out by sand filling. Compaction test: mainly ring knife method and sand filling method;
3. The crossing is on the left side of the main line, and the T-shaped crossing. The original slope of the main road is filled with a height of more than 5 meters, and in order to ensure that the filling of the crossing and the side pull of the main line slope do not settle, the main line slope is excavated and stepped treated. Make a step on the main line slope every 1 meter high on the original ground, and make a 2% cross slope in the direction of the horizontal plane of the step in the direction of the main line. When the height of the crossing filling reaches the height of the step, the roller is rolled parallel to the direction of the main line to ensure that the compaction degree of the slope is the same as that of the crossing filling.
Schematic diagram of step construction technology
6. Quality assurance measures.
1. The measuring instruments used in the construction should be calibrated regularly to the formulation unit, and the error of the instrument is found to be too large during the construction, which should be immediately sent for repair and recalibrated to meet the accuracy requirements before it can be used.
2. Check and check the measurement data provided by the design, and make up the test in time if any problems are found and report to the supervision and design processing.
3. During construction, the construction shall be carried out in strict accordance with the drawings and construction specifications.
4. Strictly implement the "three inspection system", that is, the self-inspection of the operation team, the re-inspection of the engineering department, and the three inspections of quality inspectors. Strictly implement the inspection system, and report to the supervision engineer for inspection in a timely manner.
5. During the field test, fill in all kinds of data in the test process carefully and timely to ensure the authenticity and reliability of the first filler results.
6. Actively adopt the guidance put forward by the supervision unit and the owner and improve the quality assurance measures.
7. When the embankment is filled, it should be filled in layers from the lowest place and compacted layer by layerWhen the longitudinal slope of the original ground is greater than 12% or the cross slope is steeper than 1:5, the steps should be dug according to the design requirements, and the slope of the steps should be greater than 4% inward and the width should be greater than 2m.
8. When the fill is divided into several operation sections, if the joint part cannot be filled alternately, the road section should be filled first, and the steps should be left in layers according to the 1:1 slopeIf it can be filled alternately, the layers are overlapped with each other alternately, and the lap length is not less than 2m.
9. When filling the roadbed, strictly control the quality of the filler and the moisture content of the filler, and select the appropriate compaction time. Before the subgrade is rolled, according to the moisture content of the subgrade soil, it should be properly dried or replenished to ensure that the subgrade is smooth and free of looseness. Compacting is the key. The roller first static pressure 1 times, and then start to vibrate rolling, vibration, first weak and then strong, first slow and then fast, back and forth rolling compact, from both sides to the middle of the rolling, rolling and compacting transverse joints generally overlap 1 3 wheel width, so that the rolling is uniform, no leakage, no dead end, record the number of rolling times, rolling methods and methods, rolling driving speed.
10. Strengthen the test and detection: the laboratory will send full-time testers to the site to track the test, and the test personnel will be certified to work, and each test result must be signed by the test engineer and approved by the supervision. The accuracy and sensitivity of various instruments used in the test must meet the requirements, and they should be checked regularly.
11. Compaction test: mainly ring knife method and sand filling method. When filling with various fillers, the degree of compaction is controlled according to the partition to reach more than %. 8 points per 2000 per compaction are tested.
12, subgrade filling construction control, based on the geotechnical test, its content includes the classification of filler and the use of the review, fill moisture content and density (if necessary) of the inspection, accordingly, according to the provisions of the on-site compaction machine test, determine the thickness of the filling and the number of times of rolling.
7. Safety assurance measures.
Set up a full-time safety officer and establish a 24-hour side station system to correct and eliminate unsafe signs of construction in a timely manner.
Conduct regular safety education and safety knowledge assessment for construction personnel.
Set up obvious safety warning signs and safety precautions publicity boards at the construction site.
All kinds of machinery and equipment operators must be certified to work, and unlicensed personnel or non-local personnel are not allowed to operate on the machine.
The circuit layout in the field should be standardized, and the electrical switch should be set in the electrical cabinet that is rainproof and sunproof, and the distance from the ground is not less than 15m。
6. On-site management and operation personnel must wear labor protection equipment as required.
Environmental protection measures
1. Cultural relics protection.
During the construction, if historical relics, ancient tombs, paleontological fossils and mineral deposits are found, the work will be stopped immediately, and the supervision engineer, the local government, cultural relics and relevant management departments will be reported in a timely manner, and corresponding measures will be taken to protect them, and the construction will continue after the cultural relics management department has dealt with it.
2. Protection measures for water, soil and ecological environment.
1) There is a local excavation section of the roadbed, and the construction method with the least impact on the topography, landform and vegetation is selected.
2) It is forbidden to destroy rivers, farmland and soil erosion along the slope, and the cleaned topsoil and humus soil shall be transported to the designated slag disposal site, and the slag disposal site shall be protected and greened according to the requirements of the design drawings.
3) When spoil and slag in the gully, build a retaining wall or drainage culvert pipe according to the relevant requirements of the code to prevent the formation of new sources of soil erosion. After the completion of the borrowed soil and abandoned area, it shall be leveled or recultivated or planted with grass and greening.
3. Water environmental protection measures.
1) Construction wastewater can only be discharged into the river after filtration, sedimentation or other treatment.
2) Construction close to the domestic water source, use a ditch or embankment to separate the domestic water source, and avoid polluting the domestic water source.
4. Prevention and control of atmospheric environment and dust.
1) During the construction period, the construction machinery and vehicles are often repaired, and the water is sprinkled twice a day to prevent the pollution of the countryside and crops caused by dust caused by the construction, and to prevent the harm caused to production personnel and others.
2) Lime, soil and sand and other materials are easy to fly in transportation with tarpaulin shoes to cover tightly, and the loading is moderate, it is strictly forbidden to exceed the limit, to prevent materials from spilling along the way;Rinse the tires and outside of the vehicle with water to prevent road pollution.
5. Civilized construction.
1) The construction site should be adapted to the relevant provisions of the "Several Provisions on the Civilized Construction of Construction Projects in Guangdong Province (Trial)".
2) The third division and the work area should be based on the actual situation of the process and progress of the inspection, acceptance, handover, management and other work of the protective facilities, in order to clarify the obligations, divide responsibilities and strengthen management;
3) Safety warning signs must be set up according to the regulations, and the signs must be hung in appropriate positions.
4) It is strictly forbidden to be untidy and pay attention to the corporate image
5) The machinery on the construction site is parked in an orderly manner, the materials are stacked neatly, and the construction area is kept clean and tidy
6) The construction site should be "cleaned after the completion of the work", and the surface humus of the cleaning site, the felled thorn jungle and other wastes should be transported to the designated place for disposal
7) In the process of mechanized construction, it is necessary to minimize the pollution of noise, waste gas, waste water and dust to protect the health of the people, and sprinkle water in time when the dust is too large during operation.
8) Set up civilized construction personnel on the construction site, so as to achieve dynamic management, timely collection, recording, sorting, management of ledgers and other information;
9) Establish a fire safety organization, and clarify the fire safety responsibilities of the project leader, management personnel and operation positionsAccording to the provisions of the configuration of fire-fighting equipment, there is a special person to manage;Implement fire prevention systems and measures;
10) The third division and the construction team shall set up a person in charge of civilized construction, regularly and irregularly inspect the implementation of civilized construction measures, and organize teams to carry out the activity of "creating a civilized team competition".
11) The construction site is complicated with vehicles, and a special person should be set up to command.