THURSDAY, FEBRUARY 10, 1977
SAU MAU PING LANDSLIDE REPORT
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THE GOVERNMENT HAS ACCEPTED THE FINDINGS OF THE SAU MAU PING LANDSLIDE REPORT PREPARED BY THE INTERNATIONAL PANEL OF EXPERTS COMMISSIONED BY THE GOVERNOR, AND THE SEPARATE REPORT BY THE SPECIALIST FIRM OF CONSULTANT ENGINEERS, BINNIE AND PARTNERS.
A SPOKESMAN SAID TODAY THE GOVERNMENT HAS ALREADY BEGUN IMPLEMENTING THEIR RECOMMENDATIONS.
BOTH THE REPORTS ON THE FAILURE OF THE FILL SLOPES BEHIND BLOCK 9 AND 15 OF THE ESTATE ON AUGUST 25 LAST YEAR ARE NOW BEING PRINTED IN ENGLISH AND CHINESE AND WILL BE PUBLISHED IN THE NEAR FUTURE.
THE REPORTS CONCUR IN FINDING THAT THE PRINCIPAL CAUSE OF THE LANDSLIPS WAS SURFACE INFILTRATION OF RAINWATER INTO THE SLOPES, AND THAT THE SLOPES HAD NOT BEEN SUFFICIENTLY COMPACTED.
STUDIES UNDERTAKEN BY THE PANEL OF SIX EXPERTS HAVE DETERMINED THAT THE SPECIFICATIONS SET DOWN FOR THE SLOPES' COMPACTION, ALTHOUGH OF A STANDARD WIDELY ACCEPTED AND USED AT THE TIME OF CONSTRUCTION IN THE EARLY SIXTIES, WERE NOT RIGOROUS ENOUGH TO WITHSTAND THE SEVERE RAINFALL CONDITIONS OF AUGUST 25 LAST YEAR.
THE REPORTS ADD THAT THE METHOD USED TO PLACE THE FILL MATERIAL ALSO IN GENERAL USE AT THE TIME - WAS NOT STRICTLY IN KEEPING WITH THE SPECIFICATIONS AND COULD NOT PRODUCE SOIL DENSITIES CAPABLE OF PREVENTING WHAT WAS NOW KNOWN TO BE A CRITICAL DEGREE OF RAINWATER INFILTRATION.
THE EXPERTS' INVESTIGATIONS HAVE SHOWN THAT ABNORMALLY HEAVY AND PROLONGED RAINFALL ON SLOPES BUILT IN THE MANNER OF THE EARLY 'SIXTIES CAN CAUSE WHAT THEY TERM A +MUD AVALANCHE+ BY LIQUIFYING THE TOP LAYERS OF THE TYPE OF FILL MATERIAL USED FOR SUCH SLOPES
IN HONG KONG. THE PARTICULAR PATTERN OF RAIN DURATION AND RAIN INTENSITY NECESSARY TO CAUSE A +MUD AVALANCHE+ WILL VARY FROM SLOPE TO SLOPE.
THE EXPERTS DISCOVERED THAT THE TYPE OF DECOMPOSED GRANITE USED IN HONG KONG'S FILL SLOPES REQUIRES A HIGH DEGREE OF COMPACTION IN ITS SURFACE LAYERS TO ELIMINATE ALL RISK OF MUD AVALANCHES.
THE GOVERNMENT SPOKESMAN SAID THESE STRICT NEW STANDARDS OF COMPACTION ARE NOW BEING APPLIED IN HONG KONG.
THE INTERNATIONAL PANEL OF EXPERTS ALSO SAYS THAT IN THE LIGHT OF ITS INVESTIGATIONS IT IS NOW CLEAR THAT THE SLOPE INVOLVED IN THE JUNE 1972 LANDSLIDE AT SAU MAU PING FAILED FOR SIMILAR REASONS.
THE GOVERNMENT SPOKESMAN SAID THAT DESPITE THE FACT THAT THE SAU MAU PING SLOPES WHICH FAILED IN 1972 AND 1976 WERE BUILT IN A MANNER COMMONLY ADOPTED AND WIDELY ACCEPTED THROUGHOUT THE EARLY 'SIXTIES, THE GOVERNMENT CONSIDERED IT HAD A SPECIAL RESPONSIBILITY FOR THE SAFETY OF THE SLOPES WHICH IT BUILDS.
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