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Xue L.-Y.,China Academy of Building Research | Xue L.-Y.,State Key Laboratory of Building Safety and Built Environment
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2013

Combined with a retaining structure design of a high slope construction, the engineering characteristics, design method and construction points of the upright-anchored pile retaining wall are introduced. The calculation model for the retaining structure is emphatically discussed. The stability problem of retaining structure can be viewed as strength problem. The calculation method is put forward and divided into four steps. The first step is to calculate and analyze the stability of the slope above the roof of retaining wall; and then the pile columns and prestressed anchor can be calculated and analyzed as the model of pile-anchor support system; the third step is to calculate the retaining wall; the last step, the structures of trimmers and anchor walls can be calculated. This retaining structure, which is clear and suitable for high fill slope supporting, enlarges the usable range of the retaining wall and reduces the section of upper part of retaining wall and the disturbance to the slope. It's worth promoting.


Xue L.-Y.,China Academy of Building Research | Xue L.-Y.,State Key Laboratory of Building Safety and Built Environment | Li R.-N.,China Academy of Building Research | Li R.-N.,State Key Laboratory of Building Safety and Built Environment
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2013

The characteristics and modes of failure of deep foundation pits are introduced. The internal factors of accident reason are discussed. For the accident of subway foundation ditch, the existing problems in the design, construction and monitoring are analyzed. The main reasons of the accident are that the shear-resistance rungs are not installed according to the design requirements between steel wailings and soldier piles, resulting in that the joints between steel wailings and soldier piles cannot support effectively the tangential component force of axial force of diagonal bracings, and the sliding friction between steel wailings and side wall of ditch is aroused, so the structural supports lose bearing capacity. The diagonal bracings and corbels are not welded according to the design requirements. The mechanism of load-carrying of support system in the direction of gravity changes essentially, as a result, without effective anti-sliding constraints, the steel wailings exhibit overturning and unstability, and one end of the steel diagonal bracings falls freely. Deep foundation pits should enhance the process management and control of construction quality, related parties should enhance intercommunication, and construction units should grasp the main design intention and the key design link. The unusual underlying reasons of monitoring data should be comprehensively analyzed, and specific emergency measures should be proposed.


Liu J.,Heilongjiang Province Construction Engineering Group Co. | Liu M.,State Key Laboratory of Building Safety and Built Environment | Xiao H.,State Key Laboratory of Building Safety and Built Environment
Proceedings - 5th International Conference on Instrumentation and Measurement, Computer, Communication, and Control, IMCCC 2015 | Year: 2015

This paper indicated that aligning conductive filler in the composite was an effective approach to enhance the sensitivity and measuring range of the composite. Also, the dependence of the strain gauge factor of the composite on the Poisson ratio decreased upon the aligning level of the conductive filler till vanished for a perfect aligning. The measuring rang of the conductive composite increased upon the volume concentration of conductive filler. However, an adverse effect accompanying with this benefit the piezoresistivity was the decrease in strain gauge factor. Therefore, the volume concentration and aligning level of the conductive filler should be optimized upon the requirement on the piezoresistivity. © 2015 IEEE.


Yu W.,State Key Laboratory of Building Safety and Built Environment | Yu W.,Tianjin Chengjian University
Applied Mechanics and Materials | Year: 2014

Efficient airflow delivery is key to achieve effective contamination control for a high-performance cleanroom. The influence of airflow organization on effect of particles removal in cleanroom with non-unidirectional airflow was investigated in this paper. A series of experiments were conducted on a cleanroom experimental platform with different airflow organization modes and supply air volume variation by frequency converter (40 to 50 Hz, 5Hz interval) on air-supply fan unit. The results showed that higher cleanliness could be gained at local area in cleanroom with radial airflow organization. Moreover, the outcomes from these experiments indicated that particle concentration at measuring points appeared more orderly when the cleanroom operated with radial airflow organization. The conclusion can be drawn that radial airflow can benefit contamination control at local area for cleanroom operation with non-unidirectional airflow when compared with ceiling-supply and wall-return airflow organization. © (2014) Trans Tech Publications, Switzerland.


Li W.,Tianjin Chengjian University | Li W.,State Key Laboratory of Building Safety and Built Environment | Li W.,Tianjin University | Wang Y.-H.,Tianjin Chengjian University | Kong C.-C.,Tianjin Chengjian University
International Communications in Heat and Mass Transfer | Year: 2015

In this paper, the melting and solidification processes and the thermal conductivity enhancement of the phase change material (PCM) inside a sphere have been experimentally investigated to facilitate a greater understanding and improvement of the phase change heat transfer of PCM inside a sphere. The experiments are conducted by inserting a sphere filled with organic PCM into a constant temperature bath of hot/cold water. Through measuring and analyzing the temperature field inside the sphere under conditions of various initial and final temperatures, the thermal characteristics of melting and solidification processes of PCM are obtained. To determine the thermal conductivity enhancement effect of aluminum powder, the PCM-aluminum composite material in which the mass fractions of aluminum are 1% and 2%, respectively, is tested. And the experimental data of PCM-aluminum composite material are compared with those of pure PCM. Results indicate that the PCM in the upper part of the sphere melts faster than that in the lower part, and the PCM near the inner wall solidifies faster than that in the center of the sphere. The initial PCM temperature has little effect on the solidification process of the PCM inside the sphere when Stefan number (Ste) is small and Rayleigh number (Ra) is large. The thermal conductivity of the PCM inside the sphere is enhanced by adding aluminum powder. And the sedimentation of aluminum powder is more beneficial to accelerate the heat transfer of the whole sphere in the melting process, compared with the uniform diffusion of aluminum powder in the PCM. © 2015 Elsevier Ltd.


Zhou R.,Nanjing University of Technology | Zhou R.,State Key Laboratory of Building Safety and Built Environment | Zhang W.,73677 PLA troops | Zhao D.,Nanjing University of Technology
Research Journal of Applied Sciences, Engineering and Technology | Year: 2013

In order to control the smoke diffusing and prevent the damage to the people, the smoke temperature was researched. In high-rise building fires, the most immediate threat to passengers' life is not the direct exposure to fire but the smoke inhalation because it contains hot air and toxic gases, so it has positive meaning to find the rules of the smoke temperature distribution. The variable rule of smoke temperature field distribution in passages of highrise building was the foundation of fire fighting project. Heat-transfer process between smoke and building walls was analyzed by establishing difference equation of heat balance and diffusion process between smoke and transverse passage of high-rise building was analyzed by mathematical model of air mixed with smoke. The variable rule of smoke temperature, diffusion time and length of exit passageway was analyzed by case. Smoke temperature variation in smoke diffusion process was affected mainly by generation quantity of smoke and less affected by heattransfer process between smoke and building walls. © 2013 Maxwell Scientific Organization.


Zhang J.,State Key Laboratory of Building Safety and Built Environment
Advanced Materials Research | Year: 2012

By experimental study, a design for pressurization system in a multiple injection system with upper injection is discussed and the velocity distribution in a shaft is educed by the approach method. This velocity has a relation with volume flux from pressurization fan, section area of pressurization shaft and height of shaft. In factual situation, there is an important assistant meaning on researching the design of pressurization system in high-rise buildings. © (2012) Trans Tech Publications.


Qu S.,University of Science and Technology Beijing | Qu S.,State Key Laboratory of Building Safety and Built Environment | Luo H.,University of Science and Technology Beijing
Applied Mechanics and Materials | Year: 2011

Taking thermal parameters such as evaporating temperature, condensing temperature, superheating temperature and sub-cooled temperature as the basic variables and serving COP and heating capacity as evaluating indicators, this paper builds a series of mathematical models according to the rationale of WSHP and the correlation of its components and a simulation platform based on Laboratory Virtual Instrument Engineering Workbench (LabVIEW), simulates and analyzes the influence of thermal parameters on the performance of WSHP under variable working condition. The results show that evaporating temperature and condensing temperature have more significant effect on the performance of WSHP than both of superheating temperature and sub-cooled temperature and lower condensing temperature and higher evaporating temperature can raise the value of COP but reduce heating capacity. They also show that lower superheating temperature will bring higher value of COP but lower heating capacity and higher sub-cooled temperature can make both COP value and heating capacity increase. On the simulative condition, the influence rates of evaporating temperature, condensing temperature, superheating temperature and sub-cooled temperature relative to COP of WSHP respectively are 2.25%, 2.61%, 0.7% and 0.51% and the influence rates of these temperatures relative to heating capacity respectively are 1.32%, 1.09%, 0.58% and 0.77%. These results may provide with some reliable foundations on optimizing operation and control of WSHP under variable working condition. © (2011) Trans Tech Publications.


Ji J.,Hefei University of Technology | Ji J.,State Key Laboratory of Building Safety and Built Environment | Zhong W.,Zhengzhou University | Li K.Y.,Hefei University of Technology | And 4 more authors.
Tunnelling and Underground Space Technology | Year: 2011

To assess the impact of smoke on the ceiling in subway stations, the maximum smoke temperature under the ceiling was studied theoretically and experimentally with two sets of small-scale experiments conducted. The results show that the maximum smoke temperature under the ceiling complies with the Alpert equation in which fire keeps distant from the walls in subway stations whereas fire adjacent to the end wall leads to the maximum smoke temperature under the ceiling decaying exponentially against the increased distance between the fire and the wall. In addition to the Alpert equation, a correlation determining the maximum smoke temperature is developed by taking the end wall effect into account. Consequently, a simplified calculation method involving the Alpert equation and the correlation is established. The method is applicable to practical fire engineering designs for subway stations. © 2011 Elsevier Ltd.


Wu J.H.,State Key Laboratory of Building Safety and Built Environment | Wu J.H.,Yanshan University | Li H.S.,Yanshan University
Applied Mechanics and Materials | Year: 2014

In China, it covers a sea area of about 4.73 million square kilometers, with a mainland coastline of about 18 thousand kilometers. Seawater is ideal as a heat source or sink of heat pump for heating or cooling and seawater source heat pump (SWHP) technology is a promising way to utilize ocean thermal energy. At present, SWHP has been well used in China. The article presents the application of SWHP in some cities, such as Dalian, Tianjin and Qingdao etc. Summary of these successful practical experiences of SWHP aims at informing the design for other similar projects. © (2014) Trans Tech Publications, Switzerland.

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