Location flooding
Compaction grouting constructionDue to the construction timeline being in spring and the region experiencing dry, low rainfall during that season, no drainage ditches were installed during the early stages of construction, leading to extensive flooding during precipitation. In response to this situation, the following measures have been adopted: ① Soil affected by waterlogging must be completely removed and cleaned before proceeding to the next stage of work; ② The fill area should maintain a certain cross slope or a central elevation with slightly lower ends to facilitate drainage; ③ Open drainage ditches should be excavated around the fill area, connected to sedimentation wells, and the water from these wells pumped out using pumps. Sedimentation wells should be set at each corner of the fill area or every 20 to 40 meters.
2. Excavation backfill settling
The backfill soil in the foundation pit has shown some settlement. If foundation settlement occurs after the construction of the road structural layer, it could lead to cracking of the road structural layer and overall damage. Prevention and control measures: ①Before backfilling, the silt, branches, garbage soil, and other debris at the bottom of the pit in the fill area should be cleaned up and the accumulated water drained; ②The backfill soil should be filled and compacted in strict layers, with the thickness of each layer of loose soil ≤ 300mm. The backfill material and moisture content should meet the specifications, and the dry soil quality density should be tested and meet the standard requirements; ③The backfill soil should not contain soil blocks with a diameter greater than 50mm, and there should not be an excessive amount of dry soil blocks; ④If settlement continues to develop, it is necessary to excavate the backfill soil and refill with permeable clay or silt clay, or use 2:8 or 3:7 lime soil, compacting it again.
3. The filling soil exhibited tension soil.
During the compaction of reinforced soil fill, the area subjected to force sinks while the surrounding area rises, forming a plastic condition, and stepping on it feels like stepping on a spring. This is due to the excessive water content in the soil, which exceeds the required water content for the specified compaction degree. Solutions: ① Remove organic soil and silt, control the water content of the backfill, and dry the fill soil before backfilling; ② Improve the drainage facilities around the fill soil to prevent surface water and construction water from entering the fill area; ③ Mix absorbent lime powder, crushed stone, and other materials with rubber soil to absorb the soil moisture, thereby reducing the soil water content. If the construction is urgent, remove the rubber soil entirely and replace it with 2:8 or 3:7 lime soil to compact it densely.
