.A
October 1966. Wall panels in position and awaiting the next floor slabs
pressure, two oil jacks were inserted between the floors at 6th floor level for the first test and at the 4th floor for the second test. Lateral loading was applied in the first case until the shearing force and bending moment of the testing block was equivalent to the design values at the 4th floor level.
In the second test, the two oil jacks were inserted at the 4th floor level and loading was applied until the shearing force and the moment were equivalent to the designed values at the ground floor level immediately above the in-situ structure. Loading was applied until it reached the designated load in four equal incre- ments of 25 per cent each.
Since the superstructure of the best block was completely separated from the adjoining block above ground, a datum line was set on the adjoining block for the measurement of deflec- tion and the displacement of the test block due to the applied lateral loading.
Measurements of the displacement of the test block at each floor, relative displacement of wall and floor panels, angle of deflection at the elevation of 6th floor, and the rocking of the footing in the foundations were each taken with the dial gauges, and in- clinometors, whilst any development of cracks to the test blocks were checked by visual observation.
At the same time, since the footings of the test block and the adjoining block were on an integral part, great care was taken to check the displace- ment of the datum line by the dis- placement meters, travelling micros- cope and levels.
In order to cut to a minimum the number of skilled personnel assigned to the electric dial gauges and dis- placement meters and, at the same time, to shorten the time of measure- ment, a central controlling device was installed at the control room on the
controller to note the behaviour of the test block at а glance. All measurements taken by the me- chanical dial gauges, inclinometors, travelling microscopes, levels, etc. were continuously reported to the controller by an intercom system between the control room and operation floors of the test block.
Results of the Test
From the results of the measure- ments of the relative displacement of precast wall panel and floor, no dis- placement was found throughout the test except on the 3rd floor where the reading showed a relative displace- ment of 0.04 to 0.08 mm. between the loading of 200 per cent to 100 per cent. As the displacement was so small, it was considered that this
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SECTION Ð'
BUILDING
ground floor. This also enabled the Lateral loading test
34
BLOCK A
<7 PERSOND
-OIL JACK-
<S PERSON)
17 O
BLOCK 'B'
PLAN
might be due to the movement of the instrumental scale needles, because electric type dial gauges are sensitive to direct sun and sometimes to very light shocks to the floor on which they were set.
All through the test, a thorough check was maintained to find if any cracks had developed as a result of the loading but none was observed.
From the results of the test, where the loading was limited to twice the design load, the rigidity of this build- ing was considered to be comparable to any monolithic reinforced concrete building of the same design.
No ap- preciable displacements or cracks at the joint were discovered even at the time of maximum loading.
Completion of the building in January 1967 was followed by a six months maintenance period during which, as might be expected, the behaviour of the building generally was carefully examined. The Fuk Loi Estate in a small degree suffers from vibration transmitted, it is believed, from nearby industrial plants through the rock strata below ground; there were some 20 days of rain during the period concerned. with one typhoon and four other tropical storms.
Close inspections were carried out regularly by the Housing Authority's estate management staff to see if the building system produced any special maintenance problems compared with our other properties built by tradi- tional methods. None emerged, al- though a few minor leakages were noted during heavy driving rains on exposed and staircase walls, between panels where wet joints were used.
This, we think was due to rather large areas of walling not laterally supported by floors; the joint being, perhaps, disturbed after the initial setting of the wet joint, and could fairly easily be given special attention
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-EXPANSION
JOINT
OIL JACK
RF
SECTION 'A'
BUILDING
3
BLOCK'A'
BLOCK B
2
SECTIONAL ELEVATION
GD.
Far East Architect & Builder February, 1968