清淤换填施工技术交底记录.doc

交底内容：
1、清淤时应先在路基两侧临时筑堰，抽干积水，再挖除塘底淤泥软土至原状土。
2、淤泥软土清除完毕后，进行砂砾垫层（厚30cm）的施工，接着铺设土工隔栅，随后用30cm道渣和30cm素土间隔分层压实回填至地表面。
3、砂砾材料的最大粒径应小于50mm，通过5 mm筛孔的粒料应小于35%，粒径小于0.5的粒料应不大于12%，不均匀系数应小于10%。
4、砂砾垫层的施工采用机械压实碾压，将符合要求的砂砾材料经拌和均匀后摊铺在清理好的基底上。砂砾分层摊铺，逐层压实，完工后的砂砾垫层表面不能出现坑洼不平。
5、土工格栅纵横向拉伸屈服力不小于20KN/M，规格型号为TGSG20—20。
6、土工格栅应沿开挖边坡铺至原清表地面，沿路基横断面方向反包2m，纵向外翻2m。土工格栅纵向与道路横向一致，两幅间搭接采用塑料带绑扎，绑扎间距25cm，两幅间搭接宽度大于20cm，并在铺设的土工格栅上每隔2m用U型钉固定于地面。
7、铺设完毕的土工格栅应及时回填覆盖防止日晒老化。施工中禁止施工车辆在土工隔栅上行使，随时检查土工隔栅的质量，发现有折损、刺破、撕裂等，视程度或更换，或修补。修补范围超过裂口至少30cm。
8、铺设完土工格栅之后，应按照素土——道渣——素土——道渣的顺序依次往上回填。
9、道渣碎石料应有良好的级配，最大粒径小于100mm，通过75mm筛孔的粒料大于90%，小于5mm的细料占20%～40%，石料压碎值不大于35%。
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Cards on the table contents:
1, dredging should be built first in the embankment on both sides of the temporary weir, pumping out water, and then the soft soil excavation pond sludge to undisturbed soil.
2, after removal of silt soft soil, for sand and gravel cushion (thickness 30cm) of construction, then laying Geogrids, then use the 30cm and 30cm factor ballast layer compacted backfill soil interval to the surface.
3, gravel material should be less than the maximum diameter of 50mm, through the 5 mm sieve of the aggregate should be less than 35% of the aggregate size of less than 0.5 should not exceed 12%, coefficient of uniformity should be less than 10% .
4, gravel cushion construction with mechanical compaction rolling, will meet the requirements of the gravel paving material by mixing in clean-up after even a good substrate. Paving gravel layer, layer compaction, after the completion of the gravel cushion appeared rested on the jagged surface can not.
5, longitudinal and transverse geogrid tensile yield strength of not less than 20KN / M, specification model TGSG20-20.
6, geogrid should be paved along the excavated slope to clear the table the original ground-based cross-section along the direction of anti-package 2m, vertical valgus 2m. Geogrid Vertical and horizontal line the road, between two overlapping plastic with lashing, lashing spacing 25cm, width greater than the overlap between two pieces of 20cm, and geogrid laid on every 2m fixed with U-nails ground.
7, laying the geogrid should be completed in time to prevent the sun and aging backfill cover. Prohibit the construction of the construction vehicles Geogrids exercise, at any time check the quality of Geogrids, found folded, piercing, tearing, etc., depending on the extent or replacement, or repair. Patches covering more than rip at least 30cm.
8, after laying geogrid completed, should be in accordance with the factors of soil - ballast - prime territory - ballast filling up the order.
9, Road slag aggregates should have good gradation, maximum particle size less than 100mm, 75mm sieve the aggregate by more than 90%, less than 5mm of fine material, 20% ~ 40%, stone crushing value is not more than 35%.
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