(1), subgrade 1, the survey setting-out adopts three-level management, the first-level management is provided by the owner's survey control network, the second-level management is provided by the project survey room according to the control points provided by the owner, traverse points and leveling points are set at intervals of 100M on both sides of the route, and the survey class of the third-level management project department encrypts the control points at intervals of/kloc-0. The control points set by the third-level management should be compounded by the second-level management before construction. Subgrade centerline is set out by three-level management, checked by two-level management, and subgrade sideline is set out by two-level management. At the same time, according to the height of subgrade filling and slope gradient, the toe of subgrade slope and the top line of excavation section are released. The original ground elevation is measured by surveyors before clearing the platform, and the width of clearing the platform is preliminarily calculated in combination with the designed pavement elevation. The flat section shall be made every 10m, and the section with large fluctuation and small curve radius shall be encrypted. Before the subgrade is formally filled, a group of midline piles will be laid every 10m. In order to ensure the quality of subgrade rolling, it is necessary to widen 30cm on both sides of the embankment soil, and then brush the slope to meet the design width and gradient requirements after the embankment is rolled and survived.
2. During the construction of the excavation section, take 50m as the test section, move the subgrade to the designed subgrade top elevation-1cm, and record the measured data. After the lime-soil mixing and rolling is qualified, record the measured elevation again to determine the excavation depth in the next large-scale construction. Using mechanical excavation, according to the actual situation (subgrade is embankment gravel), when it reaches 50mm above the basement elevation, stop mechanical excavation and use manual bottom picking. The settlement after compaction should be considered in the construction elevation of excavation subgrade, and its value should be determined through experiments.
3. Excavation of unsuitable materials: after the table is cleared according to the design depth, there are lots that are unsuitable for subgrade filling requirements within the scope of subgrade construction, so it is necessary to formulate corresponding plans and report them to the supervision engineer for excavation and replacement. During construction, excavation shall be carried out according to the scope and depth specified by the supervision engineer, and after approval by the supervision engineer, gravel shall be used for filling.
4. For the first time, use a heavy vibratory roller for static pressure or light vibration, and then use strong vibration for compaction. The maximum running speed of the roller should not be greater than 4 km/h ... The vibration frequency of the roller should be controlled within the range of 30~45Hz. Excessive vibration frequency will reduce the compaction effect. The amplitude of the roller should be controlled at 0.7 ~ 1.8 mm, and the rolling should be pushed from both sides of the subgrade to the middle of the road, with overlapping wheel tracks 1/3 wheel width. In the first stage of construction, the compaction degree of heavy vibratory roller is tested every time it is rolled. The detection method is sand filling method. If the degree of compaction can't meet the design requirements, continue rolling until it is qualified. And record the data to guide the future large-scale construction.
When rolling, the straight line segment presses the two sides first and then the middle, and the small radius curve segment has the inner side to the outer side, longitudinally back and forth.
Should achieve no leakage pressure, no dead angle, to ensure uniform rolling. After vibration rolling, the surface of the roller is loose. In order to eliminate this defect, after vibration rolling, the roller should be statically pressed at low speed.
5. Fine leveling type: manually re-pull, and sprinkle elevation points with white ash. The grader will level 1 ~ 2 times, and timely detect the elevation, cross slope and smoothness. For the soil surface with slightly lower local elevation, it is forbidden to directly repair it with thin layers. Before repairing, manual or mechanical ploughing is required for about 10cm. At the same time, the surveyor takes some time points to measure the actual virtual paving thickness.
(2), subbase, base 1 test section By paving a 200m test section at 1+300- 1+500, the following main items are determined:
(1) construction mix design.
(2) Loose spreading coefficient of lime-fly ash macadam.
(3) Quality control of mixture.
(4) The method of paving the mixture and the applicable appliances.
(5) Adjustment and control methods of water content of mixture.
(6) Suitable machines and methods for leveling and forming.
(7) Selection and combination of compaction machinery, order, speed and times of compaction.
(8) Coordination and cooperation of transportation, paving and rolling machinery.
(9) Inspection method of compaction degree, initially determine the minimum inspection quantity of each operation section.
(10) Appropriate length of each operation section.
(1 1) Suitable thickness for one paving.
(12) subbase and base course are paved with paver.
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