摘要 :
Abstract: The Yangtze River Bridges at Ma-an-shan consists of two major
bridges. The major bridge cross over the main stream at left is a suspension
bridge with three main pylons and two major spans of 1,080 meters (3,543 ft)
i...
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Abstract: The Yangtze River Bridges at Ma-an-shan consists of two major
bridges. The major bridge cross over the main stream at left is a suspension
bridge with three main pylons and two major spans of 1,080 meters (3,543 ft)
in span length. The middle pylon of suspension bridge is the composite pylon
made up of steel structure at its upper part and reinforced concrete structure at
its lower part.
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摘要 :
Abstract: The Yangtze River Bridges at Ma-an-shan consists of two major
bridges. The major bridge cross over the main stream at left is a suspension
bridge with three main pylons and two major spans of 1,080 meters (3,543 ft)
in s...
展开
Abstract: The Yangtze River Bridges at Ma-an-shan consists of two major
bridges. The major bridge cross over the main stream at left is a suspension
bridge with three main pylons and two major spans of 1,080 meters (3,543 ft)
in span length. The middle pylon of suspension bridge is the composite pylon
made up of steel structure at its upper part and reinforced concrete structure at
its lower part.
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摘要 :
Two road underpasses each some 200m long, 16m wide and 12m high were constructed in tunnel during 2002-2003 to serve as slip roads as part of a new major trunk road (Road T7) in Ma On Shan, Hong Kong Special Administration Region....
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Two road underpasses each some 200m long, 16m wide and 12m high were constructed in tunnel during 2002-2003 to serve as slip roads as part of a new major trunk road (Road T7) in Ma On Shan, Hong Kong Special Administration Region. The tunnel excavation encountered weak, altered and metamorphosed sedimentary rock and strong granite rock. Power tools and drill & blast techniques were employed for the tunnel excavation. Due to the presence of heavily sheared stratified rocks and over extended lengths of the tunnel, the initial temporary support system adopted for the weak rock excavation comprised a combination of support canopy (forepoling), a lightweight steel set and fibrereinforced shotcrete. The initial temporary support design was re-assessed by numerical analysis (FLAC model) with a range of geological input parameters based on detailed face mapping and monitoring carried out during construction. This led to the subsequent omission of the invert strut of the steel set. The effects of blasting vibration on the closely spaced large span tunnels was monitored using seismographs and the results fed back into the design and procedures to optimise the production blasting. The vibration as detected at ground surface was monitored to be all within the allowable maximum peak particle velocity of 25mm/s. Permanent lining construction was facilitated with the use of movable lining shutters. The regular input from a specialist geotechnical advisor to the contractor helped improve the efficiency of the construction sequence and the excavation for the underpasses was completed one month ahead of programme.
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摘要 :
Two road underpasses each some 200m long, 16m wide and 12m high were constructed in tunnel
during 2002-2003 to serve as slip roads as part of a new major trunk road (Road T7) in Ma On Shan,
Hong Kong Special Administration Regio...
展开
Two road underpasses each some 200m long, 16m wide and 12m high were constructed in tunnel
during 2002-2003 to serve as slip roads as part of a new major trunk road (Road T7) in Ma On Shan,
Hong Kong Special Administration Region. The tunnel excavation encountered weak, altered and
metamorphosed sedimentary rock and strong granite rock. Power tools and drill & blast techniques
were employed for the tunnel excavation. Due to the presence of heavily sheared stratified rocks and
over extended lengths of the tunnel, the initial temporary support system adopted for the weak rock
excavation comprised a combination of support canopy (forepoling), a lightweight steel set and fibrereinforced
shotcrete. The initial temporary support design was re-assessed by numerical analysis
(FLAC model) with a range of geological input parameters based on detailed face mapping and
monitoring carried out during construction. This led to the subsequent omission of the invert strut of
the steel set. The effects of blasting vibration on the closely spaced large span tunnels was monitored
using seismographs and the results fed back into the design and procedures to optimise the production
blasting. The vibration as detected at ground surface was monitored to be all within the allowable
maximum peak particle velocity of 25mm/s. Permanent lining construction was facilitated with the use
of movable lining shutters. The regular input from a specialist geotechnical advisor to the contractor
helped improve the efficiency of the construction sequence and the excavation for the underpasses was
completed one month ahead of programme.
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摘要 :
The purpose of this study is to quantify the relationships between the grain size characteristics and physicomechanical properties of selected marble rocks from Ma On Shan, Hong Kong. The rock specimens can be subdivided into whit...
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The purpose of this study is to quantify the relationships between the grain size characteristics and physicomechanical properties of selected marble rocks from Ma On Shan, Hong Kong. The rock specimens can be subdivided into white, light grey and dark grey, depending on the amount of impurities of the original limestone before metamorphism takes place. A series of laboratory tests, including the point load test, Schmidt hardness test, and uniaxial compression test, have been carried out on the same set of core samples in accordance with the procedures given by ISRM. Also microscopic observations based on the double replica method have been made to quantify the microphysical characteristics, in particular the grain size. The results are statistically analyzed and some selected physical and mechanical properties of the marble rocks are plotted against each other in order to explore possible relationships. The study in particular examines the influence of grain size characteristics on the engineering properties of the chosen marble rocks.
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摘要 :
The purpose of this study is to quantify the relationships between the grain size characteristics and physicomechanical properties of selected marble rocks from Ma On Shan, Hong Kong. The rock specimens can be subdivided into whit...
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The purpose of this study is to quantify the relationships between the grain size characteristics and physicomechanical properties of selected marble rocks from Ma On Shan, Hong Kong. The rock specimens can be subdivided into white, light grey and dark grey, depending on the amount of impurities of the original limestone before metamorphism takes place. A series of laboratory tests, including the point load test, Schmidt hardness test, and uniaxial compression test, have been carried out on the same set of core samples in accordance with the procedures given by ISRM. Also microscopic observations based on the double replica method have been made to quantify the microphysical characteristics, in particular the grain size. The results are statistically analyzed and some selected physical and mechanical properties of the marble rocks are plotted against each other in order to explore possible relationships. The study in particular examines the influence of grain size characteristics on the engineering properties of the chosen marble rocks.
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摘要 :
Marble is not very common in Hong Kong, it accounts for only 3% of the geological area. Despite this fact, marble and the cavities associated, play an important role within the building strategies of the city, being located in are...
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Marble is not very common in Hong Kong, it accounts for only 3% of the geological area. Despite this fact, marble and the cavities associated, play an important role within the building strategies of the city, being located in areas crucial for the development of new residential areas in Hong Kong. In order to better understand the issue, boreholes from Area 90 in Ma On Shan have been studied. This paper aims to study cavity distribution, size and location along with the rock profile and to provide an overview of the engineering problems associated with this geology. Ma On Shan Formation can be classified according to the current literature along with the risk that might pose to future civil engineering projects.
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摘要 :
TCM (Travel Cost Method) is one of the classic methods to assess the recreational benefits of outdoor recreational resources. Existing TCM include three basic models: ZTCM (Zonal TCM), ITCM (Individual TCM) and RUM (Random Utility...
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TCM (Travel Cost Method) is one of the classic methods to assess the recreational benefits of outdoor recreational resources. Existing TCM include three basic models: ZTCM (Zonal TCM), ITCM (Individual TCM) and RUM (Random Utility Method).the paper discusses which model could offer perfect solutions to assess the recreational benefits of the Ma-an-Shan Forest Park, and how to design the ZTCM questionnaire and sampling, based on the random field survey, the paper uses a two-stage approach for establishing the demand curve of recreation. Studies show that in 2009 the total recreational value of the Ma-an-Shan Forest Park reaching to 28.2 million yuan. Furthermore, The article compares the results with other similar research findings and puts forward the corresponding policy recommendations.
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摘要 :
Abstract: The steel and concrete composite and the rigid fixity of the tower and
girder system were used for the mid Pylon of the Yangtze River Bridge at
Ma-an-shan. Through optimizing the schedule of construction, adjusting
preci...
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Abstract: The steel and concrete composite and the rigid fixity of the tower and
girder system were used for the mid Pylon of the Yangtze River Bridge at
Ma-an-shan. Through optimizing the schedule of construction, adjusting
precisely the position of the rigid fixity of the tower and girder system, the
expected goal was achieved successfully. Additionally, the largest tower crane
called “D5200” has been made to assemble the large steel parts of which the
largest one weighed 213.2 tons.
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摘要 :
Abstract: The steel and concrete composite and the rigid fixity of the tower and
girder system were used for the mid Pylon of the Yangtze River Bridge at
Ma-an-shan. Through optimizing the schedule of construction, adjusting
pr...
展开
Abstract: The steel and concrete composite and the rigid fixity of the tower and
girder system were used for the mid Pylon of the Yangtze River Bridge at
Ma-an-shan. Through optimizing the schedule of construction, adjusting
precisely the position of the rigid fixity of the tower and girder system, the
expected goal was achieved successfully. Additionally, the largest tower crane
called “D5200” has been made to assemble the large steel parts of which the
largest one weighed 213.2 tons.
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