Chiu Pik Ki Becky. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 112-124). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.v / Table of Contents --- p.vi / List of Tables --- p.x / List of Figures --- p.xi / List of Plates --- p.xii / Chapter Chapter One --- introduction / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Trends in slope design --- p.2 / Chapter 1.3 --- Bioengineering practices --- p.3 / Chapter 1.4 --- Factors affecting slope vegetation growth --- p.4 / Chapter 1.5 --- Conceptual framework of the study --- p.5 / Chapter 1.6 --- Objectives of the study --- p.8 / Chapter 1.7 --- Significance of the study --- p.9 / Chapter 1.8 --- Organization of the thesis --- p.9 / Chapter Chapter two --- Literature Review / Chapter 2.1 --- Introduction --- p.11 / Chapter 2.2 --- Slope bioengineering practices --- p.12 / Chapter 2.3 --- Local techniques --- p.14 / Chapter 2.4 --- Factors affecting performance of slope --- p.19 / Chapter 2.4.1 --- Species selection --- p.19 / Chapter 2.4.2 --- Site characteristics --- p.21 / Chapter 2.4.3 --- Physical properties of growth medium --- p.21 / Chapter 2.4.4 --- Nutrients and fertilization --- p.23 / Chapter 2.4.5 --- Water and irrigation --- p.25 / Chapter 2.4.6 --- Management --- p.28 / Chapter 2.5 --- Summary --- p.28 / Chapter chapter Three --- Common Slope Bioengineering Techniques in Hong Kong / Chapter 3.1 --- Introduction --- p.29 / Chapter 3.2 --- Study sites --- p.31 / Chapter 3.3 --- Methodology --- p.34 / Chapter 3.3.1 --- In situ substrate measurements --- p.34 / Chapter 3.3.2 --- Substrate sampling --- p.35 / Chapter 3.3.3 --- Laboratory analysis --- p.35 / Chapter 3.3.4 --- Vegetation performance --- p.39 / Chapter 3.3.5 --- Statistical analysis --- p.39 / Chapter 3.4 --- Results and discussion --- p.40 / Chapter 3.4.1 --- Physical properties of substrates --- p.40 / Chapter 3.4.2 --- Chemical properties of substrates --- p.42 / Chapter 3.4.3 --- Vegetation performance --- p.48 / Chapter 3.5 --- Summary --- p.55 / Chapter chapter Four --- Substrate Properties and Nutrient Dynamics / Chapter 4.1 --- Introduction --- p.57 / Chapter 4.2 --- Experimental design of trial plots --- p.58 / Chapter 4.3 --- Methodology --- p.62 / Chapter 4.3.1 --- Substrate sampling and measurement --- p.62 / Chapter 4.3.2 --- Laboratory analysis --- p.63 / Chapter 4.3.3 --- Vegetation coverage --- p.63 / Chapter 4.3.4 --- Statistical analysis --- p.64 / Chapter 4.4 --- Results and discussion --- p.64 / Chapter 4.4.1 --- General substrate properties --- p.64 / Chapter 4.4.2 --- Seasonal variation in substrate properties --- p.68 / Chapter 4.4.3 --- Comparison between hydro-mulching and fibered-soil --- p.71 / Chapter 4.4.4 --- Nutrients and vegetation performance --- p.72 / Chapter 4.5 --- Summary --- p.72 / Chapter chapter Five --- Effect of Water and Management Practices on Slope Vegetation / Chapter 5.1 --- Introduction --- p.74 / Chapter 5.2 --- Rationale of the experiment --- p.77 / Chapter 5.2.1 --- Substrate thickness --- p.77 / Chapter 5.2.2 --- Irrigation --- p.78 / Chapter 5.2.3 --- Trimming --- p.78 / Chapter 5.2.4 --- Potential revegetation species besides grasses --- p.78 / Chapter 5.3 --- Methodology --- p.80 / Chapter 5.3.1 --- In situ moisture measurement --- p.81 / Chapter 5.3.2 --- Vegetation coverage --- p.81 / Chapter 5.3.3 --- Statistical analysis --- p.81 / Chapter 5.4 --- Results and discussion --- p.82 / Chapter 5.4.1 --- Dynamics of water on slopes --- p.82 / Chapter 5.4.2 --- Water content and vegetation coverage --- p.85 / Chapter 5.4.3 --- Vegetation and rooting depth --- p.89 / Chapter 5.4.4 --- Vegetal response to management practices --- p.90 / Chapter 5.4.5 --- Species trial --- p.90 / Chapter 5.4.6 --- Invasion of species --- p.92 / Chapter 5.5 --- Summary --- p.92 / Chapter Chapter Six --- Limitations of Present Bioengineering Techniques / Chapter 6.1 --- Introduction --- p.94 / Chapter 6.2 --- Physical setting --- p.94 / Chapter 6.2.1 --- Steep gradient --- p.94 / Chapter 6.2.2 --- Shotcreted slope surface --- p.94 / Chapter 6.3 --- Substrate properties --- p.95 / Chapter 6.3.1 --- Substrate thickness --- p.95 / Chapter 6.3.2 --- Compaction --- p.96 / Chapter 6.3.3 --- Presence of wire mesh --- p.96 / Chapter 6.3.4 --- Heterogeneous properties --- p.97 / Chapter 6.3.5 --- Highly organic peat moss composition and C:N ratios --- p.97 / Chapter 6.4 --- Water stress --- p.98 / Chapter 6.5 --- Vegetation on slopes --- p.99 / Chapter 6.5.1 --- Species selection --- p.99 / Chapter 6.5.2 --- Isolation from natural vegetation --- p.100 / Chapter 6.6 --- Management and maintenance --- p.100 / Chapter 6.6.1 --- Timing of hydroseeding and transplanting --- p.100 / Chapter 6.6.2 --- Maintenance requirements --- p.101 / Chapter 6.6.3 --- Poor workmanship --- p.101 / Chapter 6.7 --- Ultimate goal of slope bioengineering --- p.102 / Chapter 6.8 --- Summary --- p.102 / Chapter Chapter Seven --- Conclusion / Chapter 7.1 --- Summary of major findings --- p.104 / Chapter 7.2 --- Implications of the study --- p.106 / Chapter 7.2.1 --- Use of exotic grasses and naturalness of bioengineered slopes --- p.106 / Chapter 7.2.2 --- Substrate thickness --- p.107 / Chapter 7.2.3 --- "Irrigation under the principle of ""low maintenance""" --- p.108 / Chapter 7.3 --- Limitations of the study --- p.108 / Chapter 7.4 --- Suggestions for further research --- p.110 / References --- p.112 / Appendices --- p.125

published_or_final_version / Applied Geosciences / Master / Master of Science

This thesis investigates the mechanism of a slow moving landslide through a case study based on a full-scale field monitoring conducted in a slow moving natural slope. The slope is gentle and located within a southwest-trending valley which is about 500 meters long with an average slope angle of 17°. The slope is mainly consisted of a thin colluvium top layer and a thick completely decomposed andesite layer underneath. The slope was intersected by a natural drainage channel at its toe. Previous records indicate that the slope moved slowly during or after rainfall but there is still lack of sufficient information allowing one to fully understand the mechanism. To characterize soil properties of the slope, a detailed site investigation and laboratory tests were carried out prior to the instrumentation. The full-scale comprehensive field instrumentation had been completed at the end of 2007. The real-time monitoring system was consisted of a rain gauge, vibrating wire piezometers, moisture probes, WTDRs (water time-domain reflectometry), jet-fill tensiometers, in-place inclinometers and an automatic data acquisition system with wireless transmission ability. Field monitoring of the slope was successfully conducted for two years between 2008 and 2009. With the monitored data, spatial distribution of groundwater levels in two years was obtained. The variations of groundwater levels were analyzed with hourly rainfall; groundwater responses during selected rainfall events were also analyzed. Moisture contents and matric suctions within the shallow soils at the site were monitored and analyzed. Field measured Soil-water Characteristic Curves (SWCCs) were obtained and compared with the laboratory measured SWCCs. Variations of moisture contents measured in deep soils were also analyzed. Based on the monitored results of the hydrogeological responses; a hypothetical conceptual hydrogeological model was proposed. The subsurface deformations recorded by the inclinometers were analyzed and the deformation mode of the site was also discussed. A coupled seepage and deformation analysis was conducted based on the finite element program ABAQUS. Then, the numerical simulation results were compared with field monitored data. Consequently, the simulation results verified the hypothetical conceptual hydrogeological model. It is believed that the deformation of the slope is mainly associated with the quick rise of the groundwater table during or after the heavy rainfalls. Finally, conclusions and recommendations for future research on natural terrain landslide were given. It is hoped that the study of the slow moving slope can provide a useful reference for the future research. / published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / toc / Civil Engineering / Master / Master of Philosophy

published_or_final_version / abstract / toc / Applied Geosciences / Master / Master of Science

published_or_final_version / abstract / toc / Civil Engineering / Doctoral / Doctor of Philosophy

abstract / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Geography and Geology / Master / Master of Philosophy

published_or_final_version / Civil Engineering / Master / Master of Philosophy

published_or_final_version / Applied Geosciences / Master / Master of Science