Dynamic structural analysis is important and necessary for buildings at seismic area. Also, analysis of foundation and soil subjected to seismic forces is considered fundamental for safety of superstructure of buildings. This paper focuses primarily on the methodology of seismic analysis of piles for supporting high-rise buildings. Pseudo-static approach is recommended for analysis of piles subjected to seismic forces. Lateral forces on superstructure induced by seismic activity are taken into account along with nonlinear analysis of soil surrounding the piles, including t-z curves and p-y curves. On the other hand, liquefaction of foundation soils, which may result in settlement, may be triggered under seismic conditions. Dynamic settlement may also take place even for soils with no liquefaction. Methodologies for evaluation of seismic settlements are discussed in this paper. Finally, case studies for seismic analysis of foundation piles and for evaluation of seismic settlement for buildings are discussed.
The engineering property of Taichung gravel layer is unique in its own way. When it comes to foundation design in Taichung gravel, not much information is available for reference. In this paper, the ultimate skin friction of cast-in-place pile is evaluated based upon 7 sets of uplift test results. Among which, 3 test piles were constructed by full-cased technique, while the other 4 were by hand-dug method. The analysis showed that when the uplift of pile head reaches 2cm, the average skin friction of the top 4m is about 28 t/m2. Lower part of the pile may develop higher skin friction, which is estimated to be around 58 t/m2. Based upon the limited test results, it appears that the effect of distributed depth of gravel layer is more pronounced than construction method on skin friction.
The 101-Storey Taipei International Financial Center is located at SE boundary of Taipei Basin. Taipei (thrust) Fault is known to pass through the site vicinity. Assessed from the topographic conditions, and verified by site investigation, that the subsurface consists of lacustrine soft to stiff silty clay soil, coluvium/alluvial soils and underlain by pliocene Kwuitzulin Formation. A geotechnical site investigation program was conducted which consists of: (1)soil investigation program consists of 155-borehole sampling and large amount of field and lab testing during foundation planning, design and construction stages to define the subsurface soil, bedrock distribution, hydrographic condition and engineering characteristics; (2)geologic investigation program consists of reviewing and evaluating Taipei Fault related documents and records, drilling and sampling of 5 off-site deep borings, large amount of fossil idenfifications and carbon dating. Results indicate that Taipei Fault is about 200m from SE corner of the site, and the Fault has not being active for a minimum of 45,000 years and may be considered as non-active fault.
It is often necessary to call for Expansion Engineering of the existing buildings when the existing building space is insufficient for usage or when staged development is implemented. However the planning of Expansion Engineering is more difficult than other engineering works. Because not only the original functionality of the buildings must be maintained, but the safety of construction must be included into consideration as well. In particular, if the original buildings were aged and reconstruction work must be conducted on the same site. Due to the shortage of case studies, domestic contractors usually rely heavily on experiences and therefore lack proper planning in dealing with expansion/reconstruction engineering work. It is our sincere hope that by providing the actual and successful expansion/reconstruction work, we can explore this issue and provide further reference for later work.
Because of small land and dense population in Taiwan, high-rise buildings are constructed continually in urban area along with the economical development and urban renewing.In recent years due to the influence of earthquake and ground excavation, the building tilted accidents that may be occurred at any time. The tilted buildings if will be removed to reconstruct or restored to improve, it is usually difficult to make decision. Among the restoring methods, of which is effective and economical, it is concerned firstly by the damaged habitants. A case study of improving and restoring tilted building for a project in Taipei is presented in this paper, it wish to discuss about the treating process mechanism and select the best restoring method when the emergent accident occurred. At the same time, we also expect to get more efficient and more economical treating method for saving expenditure.
Buildings in Taiwan are getting higher and higher recently due to the economic growth. Meanwhile, the foundations of high-rise buildings are more and more important. In addition to matching up geologic and construction environment condition, the superstructure types and cost economical considerations are important evaluation factors for high-rise building foundations. Two case studies about overseas high-rise building foundations are also introduced to provide references in selection of high-rise building foundation.
TBM is an automatic rock excavation machine with continuous excavating, mucking and supporting. It works fast, disturbs low, support less, much safer and environmental impact low. It has been used worldwide for years. But the case is not many in Taiwan. Although there are so many advantages for TBM tunnelling , but under encountering bad geology, it may be shut down machine and pretreatment for smooth progressing. If the geological hazards happen, such as cave-in problem may stuck or damage to the machine, it always takes lots of time and money for remedial measures and restoration. This article briefly introduce some groundwater and geological hazards of TBM tunnelling in the world. To provide a reference of both design and construction of TBM tunnelling, may improve TBM tunnelling promotion.