Design of landslip preventive works for cut slopes in Hong Kong

Keyword(s):  
Author(s):  
T. I. Gamon ◽  
R. P. Finn

AbstractA simplified descriptive scheme and classification system is currently being used for the systematic logging of cut slopes for a 22 ha site formation project in weathered granitic rocks in Hong Kong.The site formation comprises the removal of some 1.5 million m3 of soft granitic soil and 3.5 million m3 of sound rock, and the formation of approximately 60,000 m2 of slope face. The cut slope faces are logged as they are exposed, and the slope protection and stabilisation works designed and installed as the site is lowered.A simplified descriptive scheme was considered essential to reduce the time for logging and eliminate the need for specialist logging personnel.Existing descriptive schemes were compared and the most useful, compatible indices selected. Additional indices from other authors were added where appropriate. This descriptive scheme was simplified after the site investigation stage of the works and the resultant scheme checked against the faces exposed during the excavation of 300,000 m3 of weathered granite as part of the advanced works.The finalised simplified scheme was documented as a manual, which has been used on site to standardise the descriptions, abbreviations and presentation. Once logged, the exposed weathered profile is classified into zones, and the distribution of the zones compared with a number of standard profiles to rapidly assess the stability of the ‘soil’ slopes.To date, 40,000 m2 of slope face have been logged at a scale of 1:100, and appropriate slope protection and stabilisation works designed and installed.


1982 ◽  
Vol 19 (4) ◽  
pp. 521-525 ◽  
Author(s):  
D. J. Sweeney ◽  
P. K. Robertson

A large number of steep, high cut slopes in residual soils exist in Hong Kong and many failures of such slopes have occurred, almost invariably during heavy rainfall. As a result, the long-term stability of many cut slopes is now in question.A brief review of past slope design and slope failure is presented.It has been found that the effective stress shear strength envelope of the Hong Kong soils is curved, particularly at low stress levels, and angles of friction are high. Shear strength results are presented from a series of multistage, consolidated drained, triaxial tests carried out on a typical decomposed Hong Kong granite residual soil. The results of the multistage tests are reviewed to assess the applicability of this type of test to residual soils.The importance of the curved shear strength envelope is discussed in relation to the observed slope failures.


1998 ◽  
Vol 13 (11-s4) ◽  
pp. S289-S293 ◽  
Author(s):  
SSY WONG ◽  
WC YAM ◽  
PHM LEUNG ◽  
PCY WOO ◽  
KY YUEN

Sign in / Sign up

Export Citation Format

Share Document