SL 174-2014 in English
VALIDTechnical specification for construction of concrete cut-off wall for water and hydropower projects
- Issued on:2014-10-27
- Implemented on:2015-01-27
- File Format:PDF
- Delivery:Via email within 5 business days
$873.00
Introduction
Core revision content of the specification and technological evolution
| Technical parameters | SL174-1996 | SL174-2014 | Key points of technical upgrade |
|---|---|---|---|
| Scope of application | Wall depth <70m Wall thickness 600-1000mm | Wall depth ≤100m Wall thickness 200-1200mm | Expanded ultra-deep and thin wall construction scenarios |
| Definition of thin wall | Undefined | ≤400mm | New special technical requirements for thin walls |
| Mud indicators | General requirements | Differentiated control in stages | Strengthen deep trench construction guarantee |
Analysis of key construction technologies
1. Slot hole construction quality control
The specification specifies four core indicators: hole position deviation ≤30mm, hole slope ≤4% (≤6% for special formations), the inclination of the joint pipe hole must meet the pull-out requirements, and the residual thickness of the small wall must be controlled. When using equipment such as hydraulic slot milling machine, special attention should be paid to the end hole accuracy.
2. Proportion of new wall materials
| Material type | Amount of cementitious material | Key performance indicators | Applicable scenarios |
|---|---|---|---|
| Plastic concrete | ≥240kg/m³ | Compressive strength≤5MPa | Deformation-sensitive foundation |
| Self-setting mortar | Cement100-300kg/m³ | Initial setting≥5h | Temporary anti-seepage structure |
Special working condition treatment plan
Case: Treatment of ultra-deep slot leakage
When the slot depth is greater than 80m and encounters a strong leakage layer, the specification requires: increasing the mud viscosity to 50s (Marsh funnel), adding plugging agent, and controlling the drilling speed. A hydropower station project used the pre-injected bentonite-cement slurry composite plugging technology to successfully treat the leakage of the 40m deep fine sand layer.
Implementation suggestions and precautions
- Geological supplementary survey requirements: When the designed rock embedding depth is in doubt, the depth of the additional exploration hole into the rock shall be ≥10m
- Thin wall construction: The second-stage trench length of the water jetting method shall be controlled to be 20-40mm> the length of the former
- Environmental protection measures: Waste slurry treatment shall comply with GB8978 comprehensive sewage discharge standard
Loading PDF document...
Error loading PDF. Please make sure the file is valid and try again.
We also recommend
-
SL 275-2001 in English
Field test methods for nuclear density-moisture gauges
2002-01-28 -
SL 19-2001 in English
Compilation rules of final account for completion of water capital construction project
2001-02-08
