Source:
https://scmp.com/article/84290/slope-repairs-eight-estates

Slope repairs at eight estates

WORK has started to clear the drainage holes on slopes and retaining walls on eight other Housing Society estates following the killer landslip at Kwun Lung Lau estate in Western.

Assurances were given yesterday that the society's geotechnical consultants had re-inspected the slopes and were satisfied.

A senior government official said the society had done more than required by way of slope inspection.

The eight estates with blocks built near slopes or retaining walls are Ming Wah Dai Ha in Shau Kei Wan; Healthy Village and Tanner Hill in North Point; Lai Tak Chuen in Tai Hang; Yue Kwong Chuen in Aberdeen; Lok Man Sun Chuen in To Kwa Wan; Kwun Tong Garden in Kwun Tong; and Cho Yiu Chuen in Kwai Chung.

About 19,800 families live in the estates.

The slopes are inspected by the society's consultants every year. But a re-inspection was prompted by the collapse of the retaining wall at Kwun Lung Lau during rainstorms, which had been deemed to pose ''no significant danger'' in an assessment three months before the tragedy.

But tenants were sill worried.

Ng Keu, 56, of Ming Wah Dai Ha, said there were often minor landslides on A Kung Ngam Road after rainstorms.

The estate is built on a hillside. A Kung Ngam Road was built by cutting flat slopes.

Mr Ng, whose block faces a retaining wall about three storeys high, said: ''It is very lucky that no one has been killed or injured.'' He said A Kung Ngam Road was closed for several days after a minor landslip on July 23 and part of the road was still closed yesterday.

A Kwun Tong Garden resident, Pang May-sheung, 15, whose block is built at the foot of a retaining wall, said: ''I am very scared. The collapse at Kwun Lung Lau has made me realise I am at risk too.

''I would rather stay at home than put my life in jeopardy during torrential rain.'' But the society said repairs were carried out at least once a year to ensure the slopes' stability, and additional inspections would be made after heavy rains.

Extra weep-holes had been added to slopes on Yue Kwong Chuen since last year's slope inspection detected a high water table, according to the society.

A spokesman said: ''Maintenance work, such as clearing weep-holes or removing grass, is being done on other slopes, as recommended by our consultants.

''It is only routine that the consultants in their reports regularly ask us to maintain slopes. That does not necessarily imply the slopes are dangerous.'' She said the society was about to do similar maintenance works on the Kwun Lung Lau retaining wall when the landslide took place. It was at the tendering stage.

Twenty Kwu Tung villagers were evacuated yesterday from their hillside huts in Sheung Shui because of fears of a mudslip.

CHRONOLOGY OF EVENTS APRIL 8, 1965: Plans for development of Kwun Lung Lau approved, and include an existing retaining wall and slope. FEBRUARY 1978: Wall registered as part of government survey that catalogued slopes and retaining walls in territory. Consultants' field sheet rates wall as in ''fair condition'', but classifies it as ''high risk''. JULY 1980: Wall inspected by Geotechnical Control Branch of Buildings Ordinance Office (later combined with Geotechnical Control Office in 1983).

1985: Housing Society consultants inspect drainage system of adjoining slope below Blocks B and C. No major cracks or leakage to drainage channels. JULY 1987: Wall inspected by Geotechnical Control Office [renamed Geotechnical Engineering Office in 1991] and found to be in ''good condition''.

APRIL 1993: Hong Kong Housing Society (HKHS) reminded of slope inspection and maintenance obligations.

JUNE 1994: HKHS consultants Mott Connell inspect slope and note minor leakage in manhole to east of slope and minor cracking to thin cement layer covering slope. No blocked weepholes recorded but weepholes of slope's cement cover recorded as blocked.

JULY 23, 1994: Amid heavy rains, retaining wall collapses spilling tonnes of mud and rock onto a footpath below. Five people killed, three others injured. In 1979 and between 1982 and 1994 the area was inspected by three government consultants. No signs of distress. Wall always assessed in ''fair'' or ''good'' condition.