DSpace Community:
http://hdl.handle.net/10722/38523
2024-03-29T02:03:09ZStratigraphic correlation of Centre Island, Kei Ling Ha Hoi and Sham Chung Kok
http://hdl.handle.net/10722/327667
Title: Stratigraphic correlation of Centre Island, Kei Ling Ha Hoi and Sham Chung Kok
Authors: Wong, Chuan Hin Jeremy; 黃雋軒
Abstract: The sedimentary sequences previously assigned to Tolo Harbour
Formation at Centre Island, Kei Ling Ha Hoi and Sham Chung
Kok were found to be weakly correlated based on lithological
characteristics. The sequence at Centre Island was highly
quartzose and well-sorted, suggesting a shallow marine
deposition environment. On the other hand, the sequences at Kei
Ling Ha Hoi and Sham Chung Kok was matrix-rich, lithicbearing,
and poorly sorted, suggesting a fluvial to near-shore
deposition environment.2022-01-01T00:00:00ZStatistical analyses of rock colors and decomposition grades
http://hdl.handle.net/10722/327650
Title: Statistical analyses of rock colors and decomposition grades
Authors: Wong, Wing Sum; 黃穎森
Abstract: Color is an effective indicator of rock type and states of weathering. This study analysed the relationship between rock color and decomposition grades using corebox photographs and compared the colors logged by geologists with the computer-determined colors regarding color accuracy. Six granite groups, including slightly decomposed and moderately decomposed fine-grained, medium-grained and coarse-grained granites, common rocks in Hong Kong, were chosen for this study. High-resolution corebox photographs were obtained from GEO GInfo and Dr Louis Wong of the University of Hong Kong. Their corresponding color description and rock classification were extracted from drillhole records and reviewed based on the attached photographs. One hundred and twenty numbers of 200x200 pixel sample images were cropped from rescaled and primarily calibrated corebox photographs for each slightly decomposed granite group. Fifty to sixty images were cropped for each moderately decomposed granite group, with a scale of 0.37 mm per pixel. Each 200x200 pixel sample image was further resized to 5x5, 25x25, 125x125 and 200x200 pixel subsample images for analyses of size effect. An RGB color digitising method was developed to obtain considerably accurate color values from each subsample image. The obtained RGB values were presented in tables, histograms, 3D color point models, and 2D scatter plots for comparison, and were expressed qualitatively as color descriptions by converting values from sRGB color space to CIE XYZ color space and the Munsell color system. It is concluded that notable statistical characteristics and graphical differences were present for each granite group, with grain size and decomposition grade being the two significant controlling factors of granite color. The results recommended against using sample images smaller than 25x25 pixels, i.e. 9.25 mm of physical distance. The objective color logging by conversion of three color spaces was demonstrated. Comparing the results obtained from corebox photographs with those obtained from the Anderson Road quarry site by on-site shooting, some unrepresentative samples were analysed to be related to improper photographic practice, limited color calibration and inappropriate light conditions. These findings indicate the need to specify the technical requirements of corebox photographs and further study the effectiveness of using corebox photographs for rock colour analyses.2022-01-01T00:00:00ZThe contributions of nutrients derived from lacustrine groundwater discharge on Chinese lake system
http://hdl.handle.net/10722/327647
Title: The contributions of nutrients derived from lacustrine groundwater discharge on Chinese lake system
Authors: Wu, Aiyue; 伍愛悦
Abstract: Lacustrine groundwater discharge (LGD) of 32 worldwide lakes are compiled from literatures and empirical formula to delineate the control mechanism of LGD in terms of three aspects: recharge control, discharge control and topographic control. Then 20 representative lakes on both sides of Hu Huanyong Line are employed to study the major regulators of groundwater borne nutrients to the lakes. The amount of nutrients derived from LGD is calculated based on the multiply approaches and nutrient concentrations in the adjacent groundwater, which helps to identify the contribution of groundwater borne nutrient to the lake nutrient inventories. With ArcGIS, the magnitudes of worldwide LGD and groundwater borne nutrients to the lakes are signified. In the interpretation of the contributions of nutrients derived from lacustrine groundwater discharge on Chinese lake system, this thesis aims to achieve the following items: 1) Obtain the major controlling factors on the driving forces of LGD; 2) Explore major regulators of groundwater borne nutrient to the lakes; 3) Clarify relationship between the contributions of nutrients derived from LGD and lake nutrient states in China. With ArcGIS, a significant spatial difference is signified on the worldwide LGD and the groundwater borne nutrients. According to the data interpreted from 20 Chinese lakes, the nutrients from LGD to the lake is higher on the east side of Hu Huanyong Line than that on the west side in general. The results of single factor and multivariate regression analysis shows that LGD values have relatively low correlation to precipitation, evaporation and topographic metric. Secondly, it is shown that a low relationship exists between groundwater borne nutrient to the lakes and the recharge, discharge and topographic items respectively. Similarly, A low correlation exists between lake nutrient states and the contribution of groundwater borne nutrient. The fulfillment of the study is believed to be contributive to the exploration of LGD controlling factors and provide a certain reference for water management.2022-01-01T00:00:00ZCode comparison on pile design and piling industry practice of driven piles in Hong Kong, Singapore and Shanghai, China
http://hdl.handle.net/10722/327643
Title: Code comparison on pile design and piling industry practice of driven piles in Hong Kong, Singapore and Shanghai, China
Authors: Wan, Chung Pan; 温仲彬
Abstract: Driven pile is a common type of piling system in the construction industry. Driving the
pile proper to the ground may generate a series of ground effects, especially groundborne
vibrations, heave, and settlements. Generally, the ultimate working capacity of
driven piles is regulated by the code for the design and construction. It is debatable
whether the higher working stress of driven piles can be accepted for use when the
design of driven piles can fulfil the following three general criteria. First, the ground
condition is well-investigated with a low chance of encountering the ground obstacles
(e.g., large rock fragments or boulders). Second, the ground has adequate ultimate
bearing resistance, and the settlement of a pile or pile group can comply with the code
requirements. Third, the piles can keep their integrity after driving. Referring to the
second criteria, this paper studies the relationship between ground performance (e.g.,
settlement, factor of safety, ground resistance) and different types of driven piles,
including reinforced concrete and steel structural piles installed in fine-grained and
granular soil profiles. This study compares the different geological settings, code
requirements, and industrial practices of driven piles in Hong Kong, Singapore and
Shanghai, China. A case study is used to check the pile design by complying with
different codes and design practice. The parametric study of PHC-600 and steel H-pile
305x305x223kg/m is assessed by adjusting the variables of working stress of pile
material, pile spacing and pile length on top of the design results of the case study.2022-01-01T00:00:00Z