Description of the Specific Process Scheme for Finished Resin Drainage Channel and Foundation Construction

Drainage Outlet Trench Excavation Sequence:

Pre-Construction Preparation for Finished Resin Drainage Channel

1. Construction shall not start with random excavation. Geological survey must be carried out to check hydrogeological conditions and parameters, and confirm suitable locations for drainage channel construction.
2. Before trench excavation, review and verify the setting-out lines.
3. Before excavation, inspect underground structures and existing drainage systems on site. Complete site drainage works to prevent water from flowing into the trench and affecting construction. This step is mandatory.
4. Organize construction personnel and machinery, and complete all acceptance and technical disclosures to ensure smooth completion and delivery of the works.
5. Machinery for foundation excavation and backfilling: crawler mini-excavator.

Construction Process of Finished Resin Drainage Channel

1. Use a total station to set the central axis, mark with wooden stakes. Measure the edge lines of the drainage channel with a steel ruler and mark the slope with lines. Mark boundaries and wall position lines at the same time.
2. Manually excavate soil within the setting-out area, strictly controlling the excavation depth and length per design to avoid over-excavation. Level the trench wall with dry-mixed mortar.
3. Install side formworks (processed timber), fixed with concrete nails. Install vertical supports every 1.2 m to prevent formwork displacement. Apply release agent on the contact surface between formwork and concrete.
4. Cover and cure the concrete with water within 16 hours after pouring. Under normal temperature, water at least twice a day; curing period shall not be less than 7 days.
5. Monitor weather conditions during construction, avoid working in rain, and take rainproof and waterproof measures.
6. Do not stack materials within 2.5 m around the trench. No vehicles are allowed near the foundation pit edge after excavation.
7. Install waterproof facilities around the trench and restrict access by non-construction personnel.

Foundation Excavation Notes During Construction

1. Clearly mark the excavation control line along the trench edge.
2. Manual foundation excavation shall not damage nearby structures and underground pipelines.
3. Monitor slope stability at all times; handle soil deformation immediately.
4. Inspect the trench promptly after excavation, then pour concrete cushion and seal it before proceeding to the next process.
5. Reserve a working space of at least 510 mm between the trench bottom and the foundation/cushion edge. Install drainage ditches and catch wells on both sides to drain seepage water timely.
6. Protect survey control stakes and axis piles, cover with steel cages, and assign professional surveyors to monitor their safety.
7. During excavation, check marking stakes, axis piles and formworks for firmness and alignment.
8. Monitor geological conditions and groundwater changes and keep records. If the foundation soil does not meet design requirements, coordinate with the design department for solutions.
9. Foundation excavation shall ensure slope stability; no random digging is allowed. Solve problems promptly.
10. When excavating to within 49 cm above the trench bottom, mark the horizontal line as the reference for leveling.
11. Stockpile excavated soil at least 5 m away from the trench edge, with stacking height not exceeding 4.6 m.
12. Level and trim the trench bottom after completion.
13. Transport all surplus soil off-site after compaction and stabilization.
14. Reduce vibration to the foundation after trench excavation. If foundation works are delayed, leave 0.3 m of soil unexcavated and remove it before construction.