| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. BOREHOLE DETAILS | |||
| A1 | Borehole identification — unique borehole ID assigned and recorded (e.g., BH-01, BH-02, etc.) Acceptance: Borehole ID visible on all logs and samples; marked on site plan with coordinates | Mandatory | |
| A2 | Location coordinates recorded — latitude, longitude, or site grid coordinates accurate to ±1m Acceptance: Coordinates measured with GPS or total station; marked on site location map; elevation (RL) also recorded | Mandatory | |
| A3 | Ground level elevation — RL (Reduced Level) of ground surface measured and recorded in meters MSL Acceptance: RL measured by surveyor; noted on bore log header; used to calculate depth below surface | Mandatory | |
| A4 | Boring date recorded — calendar date boring commenced and completion date noted Acceptance: Start and end dates recorded; time taken for boring documented | Mandatory | |
| A5 | Drilling method specified — method used (rotary, wash boring, auger, or percussion) documented Acceptance: Method noted on bore log; method appropriate for soil type and depth | Mandatory | |
| A6 | Casing depth recorded — depth to which casing advanced to maintain bore stability Acceptance: Casing depth noted; removed before SPT testing below this depth | Mandatory | |
| A7 | Water table depth — depth of static groundwater level measured and recorded (if present) Acceptance: Water table depth noted on first day boring; also re-measured at end of boring; water level used for corrections | Mandatory | |
| A8 | Drilling fluid recorded — type of fluid used (water, bentonite slurry, air) documented for bore stability Acceptance: Fluid type noted; bentonite slurry density if used (typically 1.05-1.15 t/m³) | Mandatory | |
| B. TEST EQUIPMENT & SAMPLER SPECIFICATIONS | |||
| B1 | Split spoon sampler dimensions per IS 2131 — OD (Outer Diameter) 51mm ±2mm, ID (Inner Diameter) 35mm ±2mm Acceptance: Sampler dimensions verified; certificate of calibration/measurement on file; sampler not deformed | Mandatory | |
| B2 | Sampler length — total sampler length 610mm ±10mm (including drive shoe and head); shovel length 150mm Acceptance: Length measured; sampler in good condition; no cracks or damage | Mandatory | |
| B3 | Hammer weight — 63.5 kg ±0.5 kg (140 lbs) used for driving sampler Acceptance: Hammer weighed; weight certificate on file; hammer in good condition | Mandatory | |
| B4 | Free fall height — hammer falls freely 750mm ±10mm (per IS 2131; international std. is 762mm/30 inches) Acceptance: Drop height measured; rope release mechanism functional; consistent drop height maintained | Mandatory | |
| B5 | Guide rod assembly — rigid steel guide rods prevent hammer sideway movement; diameter 25-38mm Acceptance: Guide rods vertical (plumb); no bending or wear; rods properly connected | Mandatory | |
| B6 | Anvil type — anvil (impact tool) properly mounted on drive head; provides uniform impact to sampler Acceptance: Anvil firmly attached; no looseness; drive head undamaged | Mandatory | |
| C. TEST PROCEDURE VERIFICATION | |||
| C1 | Borehole cleaned to test depth — remove cuttings and loosened material from bore bottom before sampler insertion Acceptance: Bore cleaned with bailer; water clear; no loose material at bottom | Mandatory | |
| C2 | Sampler seated to 150mm depth — initial seating blows recorded separately; subsequent 300mm drive is the actual test Acceptance: Seating blows (0-150mm) noted but not included in N-value; bore not pre-test at each level | Mandatory | |
| C3 | Test drive for 300mm — record blows for 3 successive 150mm penetrations (0-150mm seating + two 150mm drives) Acceptance: Blows for each 150mm segment recorded separately; pen blows counted carefully | Mandatory | |
| C4 | N-value calculation — sum of blows for last two 150mm segments (not including seating blows); N = blow 2 + blow 3 Acceptance: N-value calculated correctly; if N>50 for any 150mm, recorded as refusal | Mandatory | |
| C5 | Refusal definition — if sampler does not penetrate 150mm after 50 consecutive blows, test stopped; recorded as 50/x (e.g., 50/10 = 50 blows for 10mm) Acceptance: If refusal, record as 50 and actual penetration distance; note on log | Mandatory | |
| C6 | Test depth intervals — SPT conducted at 1.5m intervals (or per investigation plan) starting from 1.5m below GL Acceptance: Test depths recorded; depths below GL calculated and noted; interval consistency checked | Mandatory | |