| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. EXCAVATION & CLEARING | |||
| A1 | Site has been cleared of vegetation, topsoil, and debris to 300mm depth Acceptance: Complete removal of organic material; visual inspection confirms natural soil exposure | Cl. 401 — Preparation of subgrade | OK NC NA HOLD |
| A2 | Excavated subgrade profile matches design cross-section (±50mm) Acceptance: Spot checks at 100m intervals; variation < ±50mm from design profile | Cl. 401 — Grade compliance | OK NC NA HOLD |
| A3 | Soft spots and unstable areas identified and marked Acceptance: All areas with CBR < 2% identified and documented for special treatment | Cl. 401 — Subgrade stability assessment | OK NC NA HOLD |
| A4 | Surface drainage arrangements in place before compaction Acceptance: Lateral and longitudinal drainage channels provided; no standing water | Cl. 401 — Moisture control | OK NC NA HOLD |
| B. MOISTURE ADJUSTMENT | |||
| B1 | Soil moisture content adjusted to within ±2% of OMC before compaction Acceptance: Measured moisture: OMC ± 2%; achieved through watering or aeration | Cl. 401 — OMC compliance | OK NC NA HOLD |
| B2 | Uniformly distributed moisture across full width and depth (300mm minimum) Acceptance: Cross-section moisture variation ≤ 1.5% measured at 3+ locations per section | Cl. 401 — Homogeneous moisture distribution | OK NC NA HOLD |
| B3 | Watering/drying completed 24 hours minimum before compaction starts Acceptance: Moisture equilibration achieved; documented wait period | Cl. 401 — Preparation time | OK NC NA HOLD |
| C. COMPACTION OPERATIONS | |||
| C1 | Compaction equipment adequate for soil type (roller weight, vibration frequency) Acceptance: Roller: static weight ≥10 t; vibratory frequency 30-50 Hz; 3+ passes minimum | Cl. 401 — Equipment selection | OK NC NA HOLD |
| C2 | Compaction completed in uniform layers of 150-200mm thickness Acceptance: Each layer thickness: 150-200mm; 4+ passes of roller per layer | Cl. 401 — Layer control | OK NC NA HOLD |
| C3 | Compaction achieves minimum 95% Modified Proctor density Acceptance: Field density ≥95% MDD measured by core cutter or sand replacement method | Cl. 401 — Density requirement | OK NC NA HOLD |
| C4 | Adequate edge compaction with lateral overlap of 0.5m minimum Acceptance: Roller overlap ≥0.5m on each side; edges compacted to same density as main section | Cl. 401 — Edge control | OK NC NA HOLD |
| C5 | No binding or rutting of subgrade surface observed after compaction Acceptance: Surface rut depth < 25mm; no visible cracks or consolidation failures | Cl. 401 — Surface condition | OK NC NA HOLD |