Construction technology in South and treatment of

e707004304

Construction technology in South and treatment of special measures

Problem is in winter and spring freeze-thaw damage to the roadbed. The characteristics of the geological conditions, with large tracts of arable land in the road walk through the old roadbed is basically laid on edge or row irrigation canal drainage base side, so in winter and spring thaw on the more serious damage to the roadbed. For example, in May 2002 started in October opened to traffic engineering 48km of a County Road in the second year,[link widoczny dla zalogowanych], pumping in the spring because the road surface caused extensive damage roadbed, after rework the grassroots level from the road renovation, to the spring of 2004 and there are different degree of boiling, weakness, collapse subgrade deformation, the oil surface cracks. Main reason is to meet the investment limits in the case, designers will be reduced to a minimum road design standards,[link widoczny dla zalogowanych], in the year-round water for irrigation, the base not be processed, and the high fill embankment is only 50 - 80cm or so. To achieve the design documents and specifications life. Subgrade must be special treatment. Deal with such a foundation, according to the specific circumstances of causing boiling to develop treatment programs. First, excessive groundwater pumping in due. Can be used in a certain highly impermeable membrane laid on the roadbed. The role of groundwater in order to prevent or stop the capillary rise of water. Second, the subgrade soil is clay. The poor permeability of cohesive soils. Water accumulated in this soil, not easy to lost. Causing weakness. Measures could be taken is for a good wind permeable sand or gravel. Replacement water table and clay according to the thickness of layer thickness and the ice thickness determined. If the clay layer is not thick. The lower part of the good soil is permeable and the groundwater level is not high, only sand can be excavated clay replacement: If the soil is clay and the lower part of alternating sand, you want to change to the frozen soil below, and the best anti-roll osmosis membrane to block capillary water on the lower embankment be thrown away if the canal embankment close, and there are trees planted on the canal,[link widoczny dla zalogowanych], and roadbed construction is not high, and every winter and spring thaw, the road embankment will form vertical cracks. Handling of this situation,[link widoczny dla zalogowanych], we must first cut off the roots of the role of the capillary water, 05m away from the roadbed at a 1Om,[link widoczny dla zalogowanych], Shun ~ bar ditch digging roadbed. Width as the capillary effect of surface water, depending on the depth of the root system as determined in different species. After paving the way with the anti-deep film. Compacted sand and gravel should be backfilled. Then take steps to prevent the effect of groundwater on a better foundation is not just for aeolian sand filling should also be within the full width of the roadbed impermeable membrane. Completely prevent the effects of groundwater on the roadbed. For example, a road k13 +5 OO ~ kl4 +630 segment is too close by the canal, canal side planted with willow. Treated in accordance with the above method, despite freezing and thawing, Pavement still intact, and some areas off the trench just to the role of the roots of the capillary water treatment, after freezing and thawing, the roadbed and road surface longitudinal cracks are still there in varying degrees. The third problem is the soft treatment. Soft soil encountered in the mud should be used to increase the surface strength of shallow Treatment to prevent the foundation of local shear deformation. According to the soft soil, mud thickness and the embankment height, there are two common methods: The first method is a good replacement air permeable sand or gravel, aeolian sand require clean coarse sand, clay content not more than 5% requires the maximum size of gravel is not more than 5cm, strength of not less than four. Under the paving thickness. Stratified filling, layered compaction. The second method is Stone Fill. Rubble stone with weathered difficult. Generally the size of 30cm or more. Dumping should move forward with filling along the center line. And then gradually extended to both sides. Soft soil and stones above the surface, filling gaps with smaller stones and pad level, working closely with the roller rolling. In the perennial water or ponds (ponds) Lot construction. To rule out the water as the terrain, mud excavation surface. Stability and good water permeable material backfill to the regular water level above the 50cm. But sometimes encounter very deep water, the water table this year. Construction of the drainage situation is not easy, as the case should be taken when handling. If the roadbed construction is very high. You can work with water. Stability and good choice of water permeable material such as wind sand, gravel and other natural deposits from a forward, pushing forward with a loader or bulldozer, to be 50cm above the water when filled out, and then layered filling, layered crushed pressure. For example, another construction project in ~ K10 +950 ~ K12 +050 section, a large area of ponds, water depth 2. Om, while the design from the bottom of the pond embankment height in 5-6m. So on the way to work with water. To the completion of the project for two years. Through two winter. Spring thaw, no embankment deformation, collapse and so on. As a solid foundation is the foundation of high-rise buildings, as is the road embankment foundation. Without a good quality foundation, we can not guarantee a good surface quality. ~ Set construction roadbed construction should pay attention to the quality of life in order to ensure the rational road. ● '2 OO5 / 5 \