Video summary

Routine Load Test on Working Pile | Complete Details | As per IS: 2911 (Part-4) & IRC: 78

Main summary

Key takeaways

Educational

Main ideas and lessons (Routine Load Test on Working Pile)

The video explains Routine Load Tests performed on working piles—i.e., piles intended to carry the bridge/structure load.

The discussion is based on codal provisions of:

  • IS 2911 (Part 4)
  • IRC 78

Key topics covered include:

  • Frequency (how many piles/tests are required)
  • Special cases (which piles to select for testing)
  • Test load level (applied load)
  • Maximum settlement criteria
  • Duration/loading for single piles and pile groups (as per the codal logic described)

Methodology / instructions presented (structured bullets)

A) Frequency of routine load testing (how many working piles to test)

Based on IRC 78, Clause 7.9.2.4 (as quoted in the subtitles):

Routine load tests are done to reconfirm and modify the total load at the locations of the alternate foundation of the bridge.

The minimum number of tests depends on the total number of piles:

  • Up to 50 piles: minimum 2 tests
  • Up to 150 piles: minimum 3 tests
  • Beyond 150 piles: tests equal to 2% of the total number of piles, rounded to the next higher integer

Takeaway conveyed by subtitles:

  • Smaller pile groups → 2 or 3 tests
  • Larger pile groups → 2% testing, rounded upward

B) Number of routine tests as per IS 2911 (Part 4)

Based on the subtitles’ stated IS 2911 Part 4 rule:

Routine tests are required for one or more purposes (see section C).

  • Minimum: 5% of the total number of piles
  • Minimum absolute minimum: at least 1 test
  • May be increased up to 2% of total piles in special cases, depending on:
    • nature/type of structure
    • substrata/soil conditions

Note: The subtitles include an apparent inconsistency (“5%” and later “1% to 2%”). The core instruction being conveyed is that routine load tests form a fraction of total piles (with minimum 1), and may be increased depending on case particulars.

C) Purpose / when routine load tests are performed (as per IS 2911 Part 4 in subtitles)

Routine load testing is done to:

  • Check safe load determined from static analysis
  • Check geotechnical pile capacity using routine test results
  • Detect unusual performance during/after the initial test
    • If any problem is found in the initial test, routine tests are performed for reconfirmation on working piles

D) Special cases: selecting which pile(s) to test for routine load tests

Based on the subtitles (IS 2911 Part 4, Clause 5.2.1 in the text), the piles to be tested may be preferably selected based on indicators such as:

  1. Normal variation in concrete consumption

    • If concrete volume poured is more than expected (possible bulging), select that pile.

  2. Sudden drop in concrete level during construction

    • If concrete level drops suddenly (e.g., 2–3 m), suggesting displaced material and possible bulge, select that pile.

  3. Problems during boring and trimming operation

    • Example: if concrete gets jammed during concreting, select that pile.

  4. Significant variation in pile depth vs adjoining piles

    • Use boring records (which strata was faced).
    • If significant differences/problems are noted, select the concerned pile.

  5. Driving-related issues for driven piles

    • If issues are observed during driving, select that pile.

  6. Doubt from NDT / integrity test concerns

    • If pile integrity tests indicate possible defects such as:
      • bridging
      • necking
      • or a bad result
    • then select that pile for routine load testing to reconfirm design/safe load.

E) Applied load level and settlement criteria (single pile concept)

From the subtitles for routine load test:

  • Applied load for routine load test = 1.5 × working load

Settlement limit depends on pile diameter:

  • For pile diameter up to and including 600 mm: maximum settlement = 12 mm
  • For pile diameter > 600 mm: maximum settlement = 18 mm

Another condition mentioned:

  • “maximum 2% of the pile diameter, whichever is less”

So, the subtitles emphasize comparing:

  • the fixed settlement value (12 mm / 18 mm), and
  • 2% of diameter, then taking the smaller (whichever is less).

For comparison (initial test context): - Initial test applied load = 2.5 × working load (per subtitles) - Routine test applied load = specifically 1.5 × working load

F) Duration/loading for routine load test (single pile and group concept)

The subtitles state that duration of loading is specified by IS 2911 Part 4, and that there are separate videos for initial pile testing. However, exact numeric duration values are not clearly stated in the provided subtitles.

The main deliverables emphasized are:

  • the load factor
  • the settlement criteria
  • and the basic logic for group behavior

G) Routine load testing for a group of piles (group load and settlement)

For a pile group test (as described in subtitles):

  • Only some piles in the group are tested (example: 3–4 piles).
  • The total applied load is determined by:
    • (applied load per pile) × (number of piles considered in the group)

Example given:

  • If one pile takes 150 tonnes, then group applied load = 1500 tonnes (for 10 piles)

Group settlement criterion (as stated):

  • Settlement of an individual pile should not exceed 25 mm.

Sources / speakers featured

  • IS 2911 (Part 4) — referenced in subtitles as “EDGE 2911” / “EDGE 2911 part four” (likely meaning IS 2911 Part 4)
  • IRC 78 — cited as Clause 7.9.2.4
  • Video narrator/speaker — a single unidentified narrator (no name provided in subtitles) who explains the procedure and rules.

Original video