NOV 10 '87 12:03 TIBCOOL) HK GOVT
1987-11-04 18:21
APPENDIX 3
P.17
GNPJVC SHENZHEN
65769
P.17
ALTERNATIVE TECHNICAL SOLUTIONS
In overcoming the
non-conformance the aim 1s
to determine, the best practical approach which is
which is able to meet the original design criteria in all respects. The alternatives were as follow !
(1)
To remove the first layer of concrete and start again.
(2)
(3)
and
As previously described, the first layer is heavily reinforced ita removal would require ass of explosives and heavy machinery. It would also be necessary to remove the blinding concrete, waterproof membrane and screed which was placed on the rock foundation prior to constructing the first layer of the raft. However, the underlying rock foundation has been carefully excavated and
carefully excavated and prepared to the correct profiles, and its structural capability could be damaged by auch action. It is also possible that surrounding areas of the work site could also be damaged.
If an attempt was made to remove the first layer and such damage did occur, the extent of remedial measures on the rock foundations would be significant. It is not justifiable to cause this extent of disruption and possible damage if the raft can be completed to meet all criteria and standards of the original design using the existing first layer.
To accept the omission of the starter bars and continue with the remaining layers without any further modification.
This solution has
been seriously considered. However, the inclined reinforcing bars above the starter bars in question fulfill two functions. One is to contribute
contribute to the strength of the raft itself and, strictly speaking, the 260 starter bars that were installed will meet the design criteria in this
this respect. The other function ia to strengthen the gusset area higher up where the building walls join the raft. In this respect, strictly speaking,
18
the inclined bars will obtain sufficient anchoring for this purpose the remaining four layers of the raft without the starter bars in the first layer.
A technical argument could have been pursued on the abova basis and its result would be a structure which would meet the necessary design criteria. However, such an approach is not the best remedy that can developed and, although it may meet the design criteria, it cannot be described as completely equivalent to the original. Consequently, it was rejected.
To leave the first layer in place but re-start the entire construction on top (ie, construct a new first layer on top of
existing concrete).
the