During the leveling, the smoothness of the specified road arch, cross slope and joint shall be maintained
. 
(3) Ash distribution: quicklime should be fully digested 10-12 days in advance
. 
Subgrade standard loading: before each layer of filler is laid, the bottom of the next layer shall be checked with lime, and the line shall be hung, and each grid shall be paved with a car of filler according to the virtual paving thickness
. 
(5) Attention must be paid to the protection of underground pipelines, cables, cultural relics and other structures not shown in the drawings
. 
Embankment filling width: each side shall be 50cm wider than the design width of filling layer
. 
(4) Before the construction of filling subgrade, the construction of embankment test section should be carried out
. 
(6) Effective measures shall be taken for the excavation near residential areas to protect the houses in residential areas, ensure the safety of residents and construction personnel, and provide temporary access roads or bridges for the life and traffic of nearby residents
. 
(2) The stability of the slope shall be maintained during the excavation operation, so as not to damage or worry about the adjacent structures and facilities
. 
When sunning, the plow should be turned from both sides to the middle depth, then the rotary tiller should be crushed, and the rotary tiller should be turned again after drying for 2-4 hours (according to the temperature control); and then the plow should be turned from the middle to the middle depth In order to reduce the moisture content as soon as possible, the rotary cultivator should follow up the crushing and drying, and the ash distribution should be carried out when the moisture content of soil material is 2-4 percentage points higher than the optimal moisture content
.
Material management: the quality and uniformity of raw materials must be ensured, and the uneven quality of raw materials is one of the main reasons for the loose segregation and shrinkage cracks of water stabilized base.
.
In the straight section, the grader shall be used for leveling from both sides to the middle; the roller shall be used for rapid rolling in the initial leveling section immediately to expose the potential unevenness
.
The curing period is generally not less than 7 days, and the geotextile is used to cover and close the traffic
.
The following is a detailed graphic summary of the standardized management of municipal road subgrade, grass-roots, surface, etc., which is very worthy of collection! Subgrade Engineering 1
.
(4) During the whole construction period, it is necessary to ensure the smooth drainage of subgrade
.
(2) Grader leveling and sunning and crushing: the surface of grader leveling should be flat, and there should be a specified road arch; for the soil material with large water content in the borrow area, it should be broken and sunned in time after leveling
.
2
.
It should not be too dry, too wet or dry or wet
.
Pay attention to traffic closure during construction
.
The lime dosage, mixing depth and uniformity shall be checked according to the specifications, and the maximum particle size of soil after mixing shall not be greater than 20mm
.
The standardized management of engineering construction quality must follow the requirements of responsibility commitment, scheme first, model demonstration, pre class evaluation, process control, quantitative evaluation and continuous improvement, and operate in accordance with PDCA cycle, strictly control, continuous improvement, scientific organization and standardized management, so as to realize the comprehensive, stable and controllable quality of municipal road engineering
.
Once the above structures are found in the excavation, they shall be reported immediately, and the operation shall be stopped, and the site shall be protected for treatment
.
Lime stabilized soil base course (1) grid soil: restore the middle line and side piles of subgrade, calculate the stacking distance of each truck of soil according to the tonnage of the truck, and then mark the corresponding length and width grid marks on the lower bearing layer
.
(3) The subgrade filling material shall be determined by test and can only be used after meeting the specification and design requirements
.
Inspection and acceptance (7) curing: after the mixture is rolled, it should be cured in time to maintain a certain humidity
.
With manual cooperation, the above steps shall be repeated until the leveling is qualified
.
Excavation subgrade (1) before the commencement of subgrade excavation, the cross-section diagram of excavation engineering shall be submitted to the supervision engineer for approval, otherwise it shall not be excavated
.
Fill subgrade (1) embankment filling is mainly mechanical operation with manual cooperation
.
The field test shall be carried out until the specified compactness of this kind of filler can be effectively achieved; in principle, the test section shall not be less than 100m; during the test, the type of compaction equipment, the best combination method, rolling times, rolling speed and working procedure, loose paving thickness of each layer of material, moisture content of material, etc
.
Rolling continuously until the specified compactness is reached
.
Ash distribution (4) mixing: in accordance with the principle of “balanced speed, overlapping width, well mixed and thoroughly mixed”, it is better to “keep high than low” at the beginning of paving and “keep leakage than mending” at the end of paving; two stabilized soil mixers shall be used for centralized mixing, and the mixing depth shall be 1cm-2cm into the lower bearing layer
.
(8) Minimize the number of joints
.
In the joint treatment, part of the old mixture should be cut off and then laid, so that the new and old mixture are closely attached to each other, and the time interval between the new and old mixture on both sides of the joint should be shortened as far as possible
.
(6) Rolling: according to the principle of “light before heavy, edge before medium, slow before fast”, rolling shall be carried out continuously to the specified compactness; filling materials with appropriate water content shall be rolled in time to prevent loose filling materials from being exposed in the air for too long, resulting in water content loss and difficult compaction; generally within 24 hours, rolling time shall be controlled within 12 hours when the temperature is higher than 30 ℃ Sufficient compaction machines and tools must be equipped when the filling is completed within the specified period; the filling with unsuitable water content shall be adjusted before rolling to ensure that the water content is slightly greater than the optimal water content; when rolling, the rolling shall be carried out according to the principle of overlapping 1 / 2 wheel width from edge to middle, from low to high, and the rolling times and technology shall be based on the summary of the test section; if there is “spring” and loose phenomenon during rolling, the rolling shall be carried out according to the principle of overlapping 1 / 2 wheel width, Timely treatment to make it meet the quality requirements; after rolling, the test personnel shall check the compactness, and timely make up if it is unqualified; when the elevation, flatness and cross slope are unqualified, they shall timely repair before final compaction, and “thin layer patching” treatment is not allowed
.
Finished product effect base course project 1
.
(5) The filling subgrade must strictly implement the principle of “laying soil on the grid, hanging line construction and leveling by grader”, so as to make the subgrade surface flat, the side line straight and smooth, and the curve smooth, and control the “five degrees”, that is, compactness, flatness, thickness, width and cross slope
.
The lime should be evenly spread with scraper, and there should be no blank on the surface
.
Layered plate: layered plate for subgrade filling
.
After the curing period of lime soil is completed, the next process should be carried out as soon as possible to avoid shrinkage cracks after the moisture content of lime soil changes
.
Horizontal layered construction: the subgrade filling must be constructed in horizontal layers, and the loose paving thickness shall be controlled according to the grid soil
.
According to the thickness, predetermined dry bulk density and lime dosage, the lime dosage per square meter should be calculated, and the paving area of each truck of lime should be calculated
.
In order to ensure the construction quality and improve the construction efficiency, the construction is organized according to the operation procedure of “three stages, four sections and eight processes”, namely: three stages: preparation stage → construction stage → acceptance stage; four sections: filling section → leveling section → rolling section → inspection section; eight processes: construction preparation → base treatment → layered filling → paving and leveling → watering or drying → machinery Compaction → inspection and certification → subgrade surface renovation; (2) the foundation treatment shall be completed according to relevant regulations and inspected to be qualified
.
Fine leveling: leveling by grader
.
shall be recorded, and the test results can be used as the reference after being approved by the supervision engineer At the end of the test, if the test section meets the quality inspection standard, it can be used as a part of the subgrade, otherwise, it should be excavated and tested again
.
Leveling: initial leveling by bulldozer and fine leveling by grader
.
When loading soil, the quantity of soil loaded by each truck should be basically the same
.
Mixing (5) fine leveling: after the mixture is evenly mixed, the grader shall be used for preliminary shaping immediately
.
Measure the loose paving thickness of lime, and check whether the lime dosage is correct according to the loose density and water content of lime The uneven ash amount shall be treated to ensure the uniform distribution of lime on the working face
.
(3) Subgrade excavation materials shall be used as much as possible, and shall not be discarded except as specified in the drawings or determined as non applicable materials
.
Layered hanging line construction: subgrade filling layered hanging line control thickness
.
