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There shall be no loose or dangerous rocks on the slope.
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The roadbed must be uniform and dense, and the thickness of the last compacted layer on the top of the roadbed shall not be less than 10cm; The roadbed surface must be made into a crown cross slope consistent with the pavement, and the crown cross slope is about 3%; It is recommended to use a large roller for filling soil embankment in a large area.
The same filler shall be used for the full width of Subgrade in the same horizontal layer, and mixed filling is not allowed.
filling subgrade construction ① filling: common problems standardization construction requirements: delimited quantitative filling, horizontal layered filling, the maximum loose paving thickness of class I highway shall not exceed 30cm, and that of other highways shall not be greater than 50cm.
After the site investigation, the practical construction organization design and special construction scheme shall be prepared and submitted for approval according to the design requirements, the contract and the actual situation of the site.
Sufficient stability and durability are essential.
Bottom excavation is strictly prohibited.
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common problems of filling and excavation junction treatment: standardized construction requirements: fill in the half filling and half excavation section shall be filled in layers according to the design requirements.
Highway subgrade is a very important part of highway engineering.
supplement and unify the technical preparation, technical disclosure, pre job technical training, various tests, inspections, process handover and other forms, prepare and collect various data directories, survey and setting out: traverse resurvey, leveling resurvey, midline resurvey, cross-section resurvey, select representative sections for tests, and summarize the construction process and quality control measures.
Before commencement, the quality, environmental protection, safety management system and quality inspection system must be established and improved, and pre job training and technical and safety disclosure must be conducted for various construction teams and construction personnel.
The elevation of the excavated roadbed bedrock surface shall meet the design elevation requirements.
③ Common problems in leveling and compaction: standardized construction requirements: if the subgrade width is large, the grader shall be popularized for uniform leveling.
The original vegetation from the slope excavation line of the cutting section to the intercepting ditch shall be preserved.
Within 40cm below the roadbed bottom, the particle size of filler shall be less than 15cm.
2、 General subgrade construction 1 Common problems of soil cutting excavation ① temporary drainage: standardized construction requirements: complete temporary drainage facilities to ensure that there is no ponding on the construction surface, and the intercepting ditch should be connected with the drainage system smoothly with smooth water flow.
On the one hand, it is guaranteed by perfect design, on the other hand, it is realized by scientific and rigorous construction methods.
The quality of subgrade also determines the quality of pavement, The most direct impact is traffic and our life safety.
The Stone Filled Subgrade shall be equipped with high-power heavy-duty compaction machines (impact compactors) for impact reinforcement.
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trees and shrubs within the subgrade land cleared at the construction site shall be cut down or transplanted before surface clearing, and the cut trees shall be stacked outside the subgrade land and properly treated.
Fillers with different properties shall be filled in horizontal layers and sections and compacted in layers.
When the cross slope of the natural slope is steeper than 1:5, before filling the filling and excavation junction and the half filling and half excavation section, excavate upward from the foot of the filling slope into inward inclined steps with a width of not less than 2m..
The construction can be continued only when the slope of each layer meets the requirements of the design slope rate.
the type and quantity of construction equipment and personnel Mobilization Construction equipment meet the site requirements; All kinds of technicians and operators meet the bidding commitment.
② Excavation method: common problems: standardized construction requirements: Earthwork excavation and transportation must be carried out from top to bottom in order.
Sludge, swamp soil, frozen soil, organic soil, turf soil, domestic garbage, tree roots and soil containing decaying substances shall not be used.
The embankment slope shall be trimmed to be dense, straight, smooth and stable with smooth curve.
③ Common problems of slope trimming: standardized construction requirements: the excavation surface shall be trimmed every 3-4 meters when the excavation height is 3-4 meters.
Site planning, three supplies and one leveling, site signs, etc.
No traffic is allowed under the slope during operation.
The width of each layer of embankment fill shall be 30cm wider than the design width on each side.
Vibratory rollers less than 14T shall not be used.
Select the location of borrow and spoil areas on site.
Today, Xiaobian will join you to learn how to achieve standardized construction of highway subgrade! 1、 Construction preparation 1 It is generally required that site investigation and verification shall be carried out on the basis of a comprehensive understanding of design requirements and design disclosure before the commencement of subgrade.
The humus, topsoil, turf, etc.
② Standardized construction requirements for safe construction: when drilling blast holes, pumice and dangerous rocks on the slope shall be cleaned; Warning personnel must be assigned around the warning area.
The slope shall be trimmed layer by layer from top to bottom.
If it is too high, it shall be chiseled; If it is too low, it shall be filled with excavated stone chips or lime soil gravel and compacted.
on the original surface within the road width shall be cleaned, and the filling section shall be leveled and compacted according to the design requirements.
④ Common problems in safe construction: standardized construction requirements: the edges and cliffs and pit openings shall be protected, and various safety warning signs shall be set according to the site conditions.
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Spoil shall be cleared in time.
Warning signs should be set up under the spoil and the roads within the danger range of rolling stones.
common problems in Stone Filled Subgrade Construction: standardized construction requirements: the particle size of filler shall not be greater than 50cm, and shall not exceed 2/3 of the layer thickness.
Fixing Socket Angular End Nail Plate
stone cutting excavation ① common problems of excavation method: standardized construction requirements: the stone excavation slope shall be straight, smooth and flat.
No random over excavation or under excavation is allowed.
② Common problems of fillers: standardized construction requirements: the strength and particle size of fillers shall meet the specification requirements; The soil with liquid limit greater than 50 and plasticity index greater than 26, as well as the soil with water content greater than the specified, shall not be directly used as Embankment Filler.
