| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. TEST SETUP & CONFIGURATION | |||
| A1 | Test location preparation Acceptance: Pit properly prepared; bottom level ±10 mm; no loose soil or debris on bearing surface; surface suitable for bearing plate | Excavation at test location to required depth below GL; pit size: minimum 3B × 3B where B = plate dimension (e.g., for 300 mm plate, pit ≥900 mm × 900 mm); pit bottom leveled & compacted; soil surface uniform for plate bearing | OK NC NA HOLD |
| A2 | Bearing plate specification & preparation Acceptance: Plate dimensions verified; surface smooth & level; sand cushion uniform; plate position centered on test area | Square or circular steel plate: typical sizes 300 mm, 450 mm, 600 mm, 750 mm; thickness ≥25 mm; plate bottom cleaned & sandpapered for uniform bearing; plate placed on sand cushion (10 mm sand layer for soil protection per IS 1888 Clause 4.2) | OK NC NA HOLD |
| A3 | Reaction system (Kentledge or Anchor Piles) Acceptance: Reaction system stable; load/anchors adequate; no settlement during test setup; reaction beam horizontal ±5 mm | For kentledge: reaction frame anchored or weighted by heavy load (sand bags, concrete blocks) ≥2.5 times estimated bearing capacity × plate area; load stable & non-settling. For anchor piles: anchor piles (min 2, diameter ≥150 mm, depth ≥5 m) with reaction beam per IS 1888 Clause 4.3 | OK NC NA HOLD |
| A4 | Loading jack & pressure gauge Acceptance: Jack capacity sufficient; alignment vertical; gauge calibrated within 12 months; reading visibility clear | Hydraulic jack capacity ≥estimated bearing capacity × plate area × 1.5 (safety factor); jack positioned vertically above plate center per IS 1888 Clause 4.4; pressure gauge (0–500 kPa range typical) with ±1% accuracy | OK NC NA HOLD |
| A5 | Settlement measurement devices Acceptance: Two or more gauges functional; accuracy verified; frame rigid & independent; zero reading checked before test; readings within ±0.01 mm precision | Minimum 2 dial gauges (sensitivity 0.01 mm, range ≥50 mm) mounted on rigid frame independent of loading apparatus; gauges positioned diametrically opposite on plate ±150 mm from center; rigid beam or yoke supporting gauges, not touching loading frame per IS 1888 Clause 4.5 | OK NC NA HOLD |
| A6 | Seating load application Acceptance: Seating load applied & removed; gauge readings stable after seating; zero reference set before loading begins | Seating load applied (typically 70 kPa on plate) per IS 1888 Clause 5.1; held for 5–10 min to seat apparatus & measure initial settlement; load then released; dial gauges reset to zero for actual test | OK NC NA HOLD |
| B. LOADING SCHEDULE & PROCEDURE | |||
| B1 | Load increment definition Acceptance: Increment size defined & documented; typically 50 kPa increments for soils; increments uniform | Load increment (ΔP) = estimated safe bearing capacity ÷ 5 OR 50 kPa, whichever is smaller, per IS 1888 Clause 5.2. For example, if estimated SBC = 250 kPa, increment = 50 kPa. Increments uniform throughout test. | OK NC NA HOLD |
| B2 | Loading sequence & settlement stabilization Acceptance: Load increments applied systematically; settlement readings detailed; stabilization verified (rate <0.02 mm/hr); hold time ≥1 hr documented | At each load increment: load applied gradually (≤30 sec); settlement readings taken at specified intervals (0.25, 0.5, 1, 2, 4, 8, 15, 30 min, etc.) until settlement rate <0.02 mm/hr per IS 1888 Clause 5.2; minimum hold time = 1 hour per load increment | OK NC NA HOLD |
| B3 | Continuation of loading Acceptance: Loading criterion clearly defined in report; test stopped at defined limit; final load & settlement recorded | Loading continued (at stabilization) until: (a) Total settlement reaches 25 mm (typical limit per IS 6403 Clause 4.1), OR (b) Total settlement reaches B/10 (plate dimension), OR (c) Double tangent point observed on load-settlement curve, OR (d) Load reaches 1.5 × design load. Whichever occurs first. | OK NC NA HOLD |
| B4 | Failure recognition Acceptance: Failure mode identified; ultimate bearing capacity (if reached) documented; test halted at failure to avoid apparatus damage | Failure indicated by: continuous increase in settlement without increase in load (punch-through), OR load-settlement curve becomes vertical. At failure, note load at failure (Qf) per IS 6403 Clause 4.2 | OK NC NA HOLD |
| C. TEST RESULTS — LOAD-SETTLEMENT DATA | |||
| C1 | Data table — loading phase Acceptance: Data complete & legible; calculations verified; settlement values reasonable (typically 0–25 mm); dial readings match avg. settlement | Table columns: Load Increment No., Applied Pressure (kPa), Cumulative Load (kN), Settlement Dial 1 (mm), Settlement Dial 2 (mm), Average Settlement (mm), Time elapsed (min), Rate of settlement (mm/hr). All rows for each load increment until test completion. | OK NC NA HOLD |
| C2 | Unloading phase data Acceptance: Unload data recorded; rebound measured; elastic recovery calculated from total rebound; plastic deformation = total settlement − elastic rebound | After loading completion, unload in same decrements (ΔP). Record settlement (elastic rebound) at each unload step. Table format similar to loading phase: Load Step No., Pressure (kPa), Settlement Dial 1 & 2 (mm), Average Settlement, Time, Rebound rate | OK NC NA HOLD |
| C3 | Elastic & plastic deformation Acceptance: Recovery & plastic components calculated; values documented; interpretation relative to soil type provided | Elastic recovery (rebound) = total rebound during unloading (typically 10–30% of total settlement for granular soils). Plastic deformation = total settlement at max load − elastic rebound. Ratio elastic:plastic provides indication of soil compressibility. | OK NC NA HOLD |