constructions by masses of bamboo props.
These circumstances alone were bound to cause difficulty for the pile-drivers, even if subsoil condi- tion were normal and driving easy.
However, this was not the case. Investigation of the soil indicated that a fairly hard layer, overlying softer material, would be encoun tered about 12 feet down. The thickness of this hard stratum was estimated to be about 15 feet and it was known that the piles had to be driven through it. The pile- drivers were well aware that their equipment could penetrate the hard laver, but it was obvious that such unfavorable subsoil conditions would cause abnormal shock waves during the installation of the piles. seriously effecting the old buildings in the vicinity.
After completion of the shoring. piling was commenced. The fly shores across the site. which had been made with the customary bam boo poles, proved to be inadequate. The two adjoining buildings start- ed tilting so piling was stopped on the first day and for the next five days the shoring was strengthened.
Piling was resumed on the seventh day and was interrupted again four days later when it was considered that in order to avoid accidents, the foundations of the ad- joining buildings should be im. proved by means of grouting. In- trusion Prepakt (Far East) Ltd. car- ried out this work. They first sur- rounded the site with wooden sheet piles driven to a depth of about 12 feet. The purpose of this cur- tain was to prevent the grout from flowing into the soil where piling would later have to be carried out. Grouting was then carried out derneath the foundations of the ad- joining buildings.
An-
After an interval of three months to allow the foundations of the old buildings to consolidate. piling was resumed. There were no further in- terruptions.
The protruding canopies provide an ▸ interesting feature. Originally they were meant to hold individual air conditioners, but a central air - con- ditioning system was later installed.
THE HONG KONG & FAR EAST BUILDER-VOLUME 13, NUMBER 6
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