Page 152 - Civil Engineering Project Management, Fourth Edition

Site surveys, investigations and layout
137
For grading analyses of soils
4. Aset of BS sieves (woven wire) with lid and pan for each different diameter:
(a) 300mm dia – 38, 25, 19, 13, 10mm. (These can also be used for testing
concrete aggregate gradings.)
(b) 200 mm dia – 7, 5 and 3mm, and Nos. 7, 14, 25, 52, 72, 100 and 200.
5. Balance weighing up to 25kg.
6. Balance capable of weighing up to 7kg by 1g divisions.
For in situ density test (sand replacement method)

BS 1377 Part 9:1990 gives four tests of which Test 2.2 is the most useful because
it can be used on fine, medium and coarse grained soils. A metal tray with a
200mm diameter hole cut in it is placed on the formation and material is exca-
vated via the hole. The volume of the excavation is measured by pouring uni-
formly graded sand into it whose bulk density has been measured.
Apparatus required (additional to 1, 2, 3 and 6 above):

7. Small tools for excavating hole.
8. A rigid metal tray 500mm square or larger with a 200mm diameter hole
cut in it.
9. Dried clean sand all passing No. 25 sieve but retained on No. 52 or 100
sieve and suitable airtight containers for storing it. (About 20kg of this
sand will be required initially.)
10. A pouring cylinder (as BS 1377 Part 9 Fig. 4).
11. Acalibrating container 200mm diameter by 250mm (as BS 1377 Part 9 Fig. 5).
12. Air-tight containers for the excavated soil.
The method can be applied to larger test holes in soils containing some gravel;
the sand being poured in layers from a can with a top spout. A length of hose
is attached to the spout with a conical tin shield wired to the lower end, so the
sand has only a short standard free fall. Tests to fill measured containers can
show the accuracy in ascertaining the bulk density of the sand as poured.

For compaction tests

BS 1377 Part 4: 1990 describes tests using 2.5 or 4.5kg hammers on soils with
or without coarse grains.
For the 2.5kg test on fine and medium grained soils the apparatus required
(additional to items 1, 2, 3 and 6 above) is:
13. Compaction mould (BS 1377 Part 4 Fig. 3).
14. 2.5kg metal rammer and guide (BS 1377 Part 4 Fig. 4).
15. Palette knife.