XN000022-1983-04-17 — Page 2

SUNDAY, APRIL 17, 1983

GOVERNMENT SPENDING MASSIVE SUMS ON SLOPE STABILISATION

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THE MANY STABILISED SLOPES THROUGHOUT HONG KONG ARE EXPECTED TO HOLD UP WELL AGAINST RAINS IN THE COMING MONSOON SEASON.

THESE SLOPES WITHSTOOD STRENUOUS TESTS IN FEBRUARY AND MARCH WHEN TORRENTIAL DOWNPOURS OF 291.2 MM AND 428 MM RESPECTIVELY WERE THE HEAVIEST FOR THE TWO MONTHS SINCE RECORDS STARTED IN 1884.

THE ABSENCE OF ANY SERIOUS LANDSLIDES DESPITE THIS ONSLAUGHT WAS LARGELY THE RESULT OF THE MASSIVE STABILISATION PROGRAMME ON SLOPES AND RETAINING WALLS CARRIED OUT SINCE 1977, SAID DR E.W. BRAND, PRINCIPAL GOVERNMENT GEOTECHNICAL ENGINEER' WHO HEADS THE GEOTECHNICAL CONTROL OFFICE (GCO).

THIS WAS THE THIRD TIME IN LESS THAN A YEAR THAT STABILISED SLOPES HELD THEIR OWN AGAINST HEAVY RAINS, HE POINTED OUT. DURING THE SEVERE RAINSTORMS IN MAY AND AUGUST LAST YEAR, THERE WAS NO FAILURE OF ANY +ENGINEERED SLOPE+ INVOLVING CASUALTIES.

THE RAINSTORM IN MAY WAS DESCRIBED BY DR BRAND AS A ONE IN 15 YEARS EVENT AND THAT IN AUGUST AS A ONE IN EIGHT YEARS EVENT+. STATISTICALLY, HONG KONG WOULD ONLY HAVE TWO SEVERE RAINSTORMS IN ONE YEAR ONCE EVERY 120 YEARS, HE EXPLAINED.

THERE WERE INDEED MANY LANDSLIPS DURING THE TWO MONTHS, RESULTING IN 22 DEATHS IN MAY AND ANOTHER FIVE DEATHS IN AUGUST. THESE CASUALTIES, HOWEVER, WERE CONFINED ENTIRELY TO SQUATTER AREAS WHERE MEANINGFUL SLOPE STABILISATION WORK IS IMPOSSIBLE UNLESS THE SQUATTERS ARE CLEARED, DR BRAND POINTED OUT.

+WHAT WE DIDN'T HAVE IS A FAILURE OF ANY CONSEQUENCE OF ANY ENGINEERED SLOPE, HE STRESSED. THIS WAS IN SHARP CONTRAST TO THE CATASTROPHES WHICH HAD BEFALLEN HONG KONG ON SOME OCCASIONS IN THE PAST.

IN JUNE 1972, A 12-STOREY BUILDING IN THE MID-LEVELS COLLAPSED, KILLING 55 PEOPLE. IN THE SAME YEAR, AND AGAIN IN 1976, SLOPES BEHIND A HOUSING ESTATE IN KOWLOON MELTED AWAY. KILLING 71 AND 18 PEOPLE RESPECTIVELY.

IT WAS BECAUSE OF THESE DISASTERS THAT THE GCO WAS ESTABLISHED IN 1977. THE OFFICE IS THE GOVERNMENT ORGANISATION CONCERNED WITH A WIDE RANGE OF GEOTECHNICAL ACTIVITIES, WITH PARTICULAR EMPHASIS ON THE STABILITY OF SLOPES AND ON THE GEOTECHNICAL ASPECTS OF SLOPE-RELATED PROJECTS.

ENGINEERS OF THE OFFICE IMMEDIATELY MOVED INTO ACTION AND HAVE SINCE STABILISED SEVERAL HUNDRED SLOPES AND RETAINING WALLS IN DIFFERENT PARTS OF HONG KONG AT A TOTAL COST OF SOME $470 MILLION.

+PREVENTIVE WORK WAS INITIALLY FOCUSSED ON LARGE FILL OR MAN-MADE SLOPES. IT WAS FELT THESE SLOPES POSED THE GREATEST DANGER TO LIFE AND PROPERTY AT TIMES OF EXTREMELY HEAVY RAINSTORMS,+ DR BRAND SAID.

/HE EXPECTED