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1.
Li Peizhen Ren Hongmei Lu Xilin Song Heping Chen Yueqing 《Frontiers of Architecture and Civil Engineering in China》2007,1(3):346-352
Shaking table tests on a dynamic interaction system of hard layered soil, pile foundation and frame structure were carried
out. The earthquake damage of the superstructure and foundation was reproduced. Based on these tests, several key issues about
the seismic response of the dynamic soil-structure interaction (SSI) system were studied. The natural frequency of the system
was less than that of the structure on rigid foundation if the SSI is not taken into account, while its damping ratio was
larger than that of the structure. The mode shape of the system was different from that of the structure on the fixed base
in that there were rocking and swinging at the foundation. Magnification or reduction of vibration transferred by soil was
related to soil characteristic, excitation magnitude, and so on. Generally, sand magnifies vibration, while viscous powder
soil dampens vibration. The components of the acceleration response at the top of the superstructure were based on the relative
magnitude of the rocking stiffness, the swing stiffness of the foundation and the stiffness of the super-structure. The multi-direction
excitations have little effect on the key issues of the horizontal SSI.
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Translated from Journal of Tongji University (Natural Science), 2006, 34(3): 307–313 [译自: 同济大学学报 (自然科学版)] 相似文献
2.
Yiyi Chen Dazhao Zhang Weichen Xue Wensheng Lu 《Frontiers of Architecture and Civil Engineering in China》2009,3(2):117-124
The seismic behavior of a structural system composed of pre-stressed concrete stand supporting a retractable steel roof was
studied, which is typically based on the prototype of engineering project of Shanghai Qizhong Tennis Center. By elasto-plastic
finite element analysis and shaking table test, the following were investigated: the effects of roof configurations in opening
and closing, the effect of pre-stress on the structural seismic response, and the failure mechanism of the spatial stand frame
systems featured with circularly arranged columns and inverse-cone type stands. It was found that the roof status has great
effect on the natural period, vibration modes, and seismic response of the whole structure, the stand response to horizontal
seismic excitation is stronger in roof opening configuration than in closing state, and the response mode is dominantly translational
rather than rotational, though the stand is characterized by its fundamentally torsional vibration mode. The study indicated
that the pre-stressed inverse-cone stands can keep the system from global side-sway collapse under gravity loads, even in
the case that most columns loose moment capacity.
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Translated from China Civil Engineering Journal, 2007, 40(8): 22–28 [译自: 土木工程学报] 相似文献
3.
Bo Geng Hong Wang Junjie Wang 《Frontiers of Architecture and Civil Engineering in China》2009,3(3):279-285
Based on a field observation on vessel transit path of three bridges over the Yangtze River in the Three Gorges Reservoir,
and an analysis of the geometric probabilistic model of transiting vessels in collision probability calculation, the aberrancy
angle and vessel velocity probabilistic model related with impact force, a probabilistic model is established and also verified
by goodness-of-fit test. The vessel transit path distribution can be expressed by the normal distribution model. For the Three
Gorges Reservoir, the mean and standard deviation adopt 0.2w and 0.1w, respectively (w is the channel width). The aberrancy angle distribution of vessels accepts maximum I distribution model,
and its distribution parameters can be taken as 0.314 and 4.354. The velocity distribution of up-bound and down-bound vessels
can also be expressed by the normal distribution model.
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Translated from Journal of Tongji University (Natural Science), 2008, 36 (4): 477–482 [译自: 同济大学学报(自然科学版)] 相似文献
4.
Zhan Liangtong 《Frontiers of Architecture and Civil Engineering in China》2007,1(2):198-204
The intensive soil-water interaction in unsaturated expansive soil is one of the major reasons for slope failures. In this
paper, the soil-water interaction is investigated with the full-scale field inspection of rainwater infiltration and comprehensive
experiments, including wetting-induced softening tests, swelling, and shrinkage tests. It is demonstrated that the soil-water
interaction induced by seasonal wetting-drying cycles is very complex, and it involves coupled effects among the changes in
water content, suction, stress, deformation and shear strength. In addition, the abundant cracks in the expansive soil play
an important role in the soil-water interaction. The cracks disintegrate the soil mass, and more importantly, provide easy
pathways for rainfall infiltration. Infiltration of rainwater not only results in wetting-induced softening of the shallow
unsaturated soil layers, but also leads to the increase of horizontal stress. The increase of horizontal stress may lead to
a local passive failure. The seasonal wetting-drying cycles tend to result in a down-slope creeping of the shallow soil layer,
which leads to progressive slope failure.
Translated from Journal of Zhejiang University (Engineering Science), 2006, 40(3): 494–500 [译自: 浙江大学学报 (工学版)] 相似文献
5.
Zhiqiang Zhang Aiqun Li Jianping He Jianlei Wang 《Frontiers of Architecture and Civil Engineering in China》2009,3(3):249-254
The Hefei TV tower is taken as an analytical case to examine the control method with a fluid viscous damper under wind load
fluctuation. Firstly, according to the random vibration theory, the effect of fluctuating wind on the tower can be modeled
as a 19-dimensional correlated random process, and the wind-induced vibration analysis of the tower subjected to dynamic wind
load was further obtained. On the basis of the others’ works, a bimodel dynamic model is proposed. Finally, a dynamic model
is proposed to study the wind-induced vibration control analysis using viscous fluid dampers, and the optimal damping coefficient
is obtained regarding the wind-induced response of the upper turret as optimization objectives. Analysis results show that
the maximum peak response of the tower under dynamic wind load is far beyond the allowable range of the code. The wind-induced
responses and the wind vibration input energy of the tower are decreased greatly by using a fluid viscous damper, and the
peak acceleration responses of the upper turret is reduced by 43.4%.
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Translated from Journal of Southeast University (Natural Science Edition), 2008, 37(6): 1018–1022 [译自: 东南大学学报(自然科学版)] 相似文献
6.
Menggang YANG Zhengqing CHEN Jianhua HU 《Frontiers of Architecture and Civil Engineering in China》2008,2(1):43-48
To mitigate the seismic response of self-anchored suspension bridges, equations of motion governing the coupled system of
bridge-magneto-rheological (MR) dampers subject to seismic excitation are formulated by employing the phenomenological model
of MR dampers. A corresponding computer program is developed and employed for studying the seismic response control of a self-anchored
suspension bridge with a main span of 350 m. The effect of variable current and number of dampers on seismic response control
is investigated. The numerical results indicate the longitudinal displacement of the tower top and bridge girder decrease
with the increase in input current and number of MR dampers attached longitudinally at the tower-girder connections, and the
internal forces of the tower are effectively attenuated as well. It appears that small electronic current (0.5 A in this study)
may sufficiently attenuate the seismic responses for practical engineering applications.
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Translated from China Civil Engineering Journal, 2006, 39(11): 84–89 [译自: 土木工程学报] 相似文献
7.
Li Jie 《Frontiers of Architecture and Civil Engineering in China》2007,1(1):34-40
In this paper, an overview is given on several key issues and related research progress made in lifeline engineering. The
research topics include: numerical modeling of random seismic waves, probabilistic density evolution analysis for nonlinear
structural responses, and seismic reliability analysis of large-scale lifeline networks. In addition, a comparison is made
between the domestic and international studies on the aforementioned topics. Several examples are included in the paper as
the case studies. Recommendations are given for further development of the lifeline engineering research.
Translated from China Civil Engineering Journal, 2006, 39(1):1–6, 37 [译自: 土木工程学报] 相似文献
8.
In this paper, a novel “composite reaching law” was explained in details: 1) the equation of discrete motion for a control
system; 2) the design of discrete-time variable structure control. In addition, the model of a three-storey shear-type building
structure was used to verify the effectiveness of the discrete variable structure control method. The results of numerical
example analysis of the model show that the control law can effectively reduce the peak value of seismic response of the building
structure and the chattering effect of the control system.
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Translated from Journal of Northwestern Polytechnical University, 2007, 25(6): 869-873 [译自: 西北工业大学学报] 相似文献
9.
Yiqun TANG Ping YANG Feng SHEN Nianqing ZHOU 《Frontiers of Architecture and Civil Engineering in China》2008,2(3):242-245
The behavior of dark green silty soil of the 6th storey is studied by means of scanning electron microscopy (SEM). The shape,
size and contact condition of the basic elements of the soil microstructure, and the shape and the size of the pore are further
studied. In addition, a comparative study is made to analyze the experiment results of Cu and dynamic test. The mechanic characteristics
of common soil and those of melted soil are presented and their influences on dark silty soil after being frozen are theoretically
illustrated from a microscopic perspective.
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Translated from Journal of Tongji University (Natural Science), 2007, 35(1): 6–9 [译自: 同济大学学报(自然科学版)] 相似文献
10.
Hu Kexu He Guisheng Lu Fan 《Frontiers of Architecture and Civil Engineering in China》2007,1(4):399-404
In this paper, two reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP) and attached with
thick-painted fire resistant coating were tested for fire resistance following the standard fire testing procedures. The experimental
results show that the specimen pasted with the insulated layer of 50 mm in thickness could resist fire for 2.5 h. It is also
demonstrated that the steel wire mesh embedded in the insulated layer can effectively prevent it from cracking and eroding
under firing.
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Translated from Journal of Tongji University (Natural Sciences), 2006, 34(11): 1452–1456 [译自: 同济大学学报 (自然科学版)] 相似文献
11.
Wang Xiekang Wang Xianye Lu Weizhen Liu Tonghuan 《Frontiers of Architecture and Civil Engineering in China》2007,1(2):211-216
Channel confluences are common in natural rivers and hydraulic engineering, and the flow behavior at confluences becomes very
complex because of the interaction between the tributary and the main river. In this study, the experiments were performed
in a combined flume with a 30° angle between the main and tributary flume located at Sichuan University. The velocity was
measured by using a three-component acoustic Doppler velocimeter (ADV) over a grid defined throughout the junction region.
Based on the analysis of the velocity at the confluence, the distinctive characteristics of a channel confluence flow may
be divided into several zones including a zone of separation immediately downstream of the junction branch channel, the maximum
and minimum velocity regions at the upstream and downstream in the confluent channel, and a shear plane developed between
the two combining flows downstream of the confluent channel. In addition, secondary circulations in different directions at
the higher and lower velocity zones are observed as well.
Translated from Journal of Sichuan University (Engineering Science Edition), 2006, 38(2): 1–5 [译自: 四川大学学报 (工程科学版)] 相似文献
12.
Riqing Xu Yin Guo Zengyong Liu 《Frontiers of Architecture and Civil Engineering in China》2008,2(2):161-165
In order to study the influence of organic matter on the mechanical properties of stabilized soil and the effect of XGL2005
on stabilizing organic soil, unconfined compressive strength tests were carried out. Test results indicated that the strength
of stabilized soil decreased in the form of a logarithmic function as the organic matter content increased. In contrast, the
strength increased in the form of a power function as the content of the stabilization agent increased. The strength of cement
stabilized organic soil was reinforced greatly by adding the stabilizer XGL2005. Based on the law obtained from the test,
a strength prediction model was established by regression analysis. The model included the influence of the curing time, the
content of the cement, the organic matter content and the stabilization agent on the strength of stabilized soil.
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Translated from Journal of Zhejiang University (Engineering Science), 2007, 41(1): 109–113 [译自: 浙江 大学学报(工学版)] 相似文献
13.
Qi Li Dingjun Wu Xiaobin Huang 《Frontiers of Architecture and Civil Engineering in China》2008,2(2):133-138
It has been reported several times that train derailment occurs when mixed marshalling freight trains traverse bridges at
high speeds in China. This study aims to explain this phenomenon numerically based on the train-bridge coupling vibration
theory and its associated computer program. The train-bridge vibration characteristic is analyzed by a computer program when
mixed marshalling freight trains traverse 32-meter-span prestressed concrete simple beam bridges. The mechanism that dynamic
responses of the bridges are prominent and that empty trains are inclined to derail are derived from the dynamic responses
analysis. The analysis indicates that the significant differences of axle loads between heavy vehicles and empty vehicles
produce periodic forced loadings of large amplitudes. These periodic loadings cause severe vibration of bridges. In turn,
severe vibration of the bridges produces intensive counteraction to empty vehicles.
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Translated from Journal of Tongji University (Natural Science), 2007, 35(2): 171–175 [译自: 同济大学学报(自然科学版)] 相似文献
14.
Li Liang Du Xiuli Li Liyun Zhao Chenggang 《Frontiers of Architecture and Civil Engineering in China》2007,1(4):436-442
In order to describe the elasto-plastic dynamic response of fluid-saturated porous media, the incremental elasto-plastic wave
propagation equations of fluid-saturated porous media are developed by the fundamental theory of continuum mechanics and appointing
to the characteristic of fluid-saturated porous media. Then, the space discretization of these equations is performed to get
their Galerkin formula. At last, the time discretization of this formula is carried out with the integral method which consists
of central difference method and Newmark constant average acceleration method to get the explicit time integral formula for
solving the wave propagation equations of porous media. On the basis of the integral formula mentioned above, the time-domain
explicit finite element method is developed for calculation and analysis of the elasto-plastic dynamic response of fluid-saturated
porous media. In this method, the decoupling technique is adopted and it does not need to solve simultaneous linear equations
in each time step, so the computational effort and memory requirement can be reduced considerably by using this method.
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Translated from Journal of Beijing University of Technology, 2006, 32(9): 785–790 [译自: 北京工业大学学报] 相似文献
15.
Yuedong SUN Jianzhuang XIAO Research 《Frontiers of Architecture and Civil Engineering in China》2008,2(4):302-308
A study is conducted on the seismic behavior of one natural concrete frame and two recycled concrete frames with 100% recycled
coarse aggregate whose scales are 1:2 entirely, and a comparative study is conducted under low-reversed cyclic lateral loading
and different vertical loading. This work aims to estimate the failure mechanism, hysteresis loops, displacement ductility,
deterioration of strength and stiffness and energy dissipation of recycled concrete frames under low-reversed cyclic loading
as well as the influence of different vertical loading. Analysis on the basis of the experiment proves that it is entirely
feasible to apply recycled concrete to practical engineering for the sake of its good seismic behaviors. Theoretical base
is provided for further study and practical application of recycled concrete structure.
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Translated from Journal of Tongji University (Natural Science), 2007, 35(8): 1013–1018 [译自: 同济大学学报(自然科学版)] 相似文献
16.
Minshui Huang Wenzeng Guo Hongping Zhu Lin Li 《Frontiers of Architecture and Civil Engineering in China》2008,2(2):139-144
The dynamic characteristics of bridge structures are the basis of structural dynamic response and seismic analysis, and are
also an important target of health condition monitoring. In this paper, a three-dimensional finite-element model is first
established for a highway bridge over a railroad on No.312 National Highway. Based on design drawings, the dynamic characteristics
of the bridge are studied using finite element analysis and ambient vibration measurements. Thus, a set of data is selected
based on sensitivity analysis and optimization theory; the finite element model of the bridge is updated. The numerical and
experimental results show that the updated method is more simple and effective, the updated finite element model can reflect
the dynamic characteristics of the bridge better, and it can be used to predict the dynamic response under complex external
forces. It is also helpful for further damage identification and health condition monitoring.
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Translated from Chinese Journal of Huazhong University of Science and Technology (Urban Science Edition), 2006, 23(4): 57–60 [译自: 华 中科技大学学报(城市科学版)] 相似文献
17.
Hanlong Liu Xuanming Ding 《Frontiers of Architecture and Civil Engineering in China》2009,3(2):180-186
The three-dimensional effects of pile head and the applicability of plane-section assumption are main problems in low-strain
dynamic tests on cast-in-situ concrete thin-wall pipe piles. The velocity and displacement responses were calculated by a
theoretical formula deduced by the authors. The frequency and influencing factor of high-frequency interference were analyzed.
A numerical method was established to calculate the peak value and arrival time of incoming waves on top of the piles. The
regularity along circumferential and the influence of radius or impulse width were studied. The applicability of plane-section
assumption was investigated by comparison of velocity responses at different points in the sections at different depths. The
waveform of velocity response at different points forked after the first peak, indicating that the propagation of stress waves
did not well meet the plane- section assumption.
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Translated from Chinese Journal of Geotechnical Engineering, 2008, 30 (3): 414–419 [译自: 岩土工程学报] 相似文献
18.
Yiyi CHEN Ruoning BIAN Fangfang LIAO 《Frontiers of Architecture and Civil Engineering in China》2008,2(4):295-301
Impact effect of sudden fracture at steel frame connections under severe earthquake or other extreme loads is presented in
this paper. The relation of impulse caused by structural fracture to the release of inner force at the cracked location, the
magnitude of the response to impact on the basis of one degree of freedom model, and the ratio of the peak value of response
to natural period of the system are investigated. Two types of fracture tests were designed and carried out both on uniaxial
steel bar tensioned and moment resistant steel frame model. It is proven that the response during the fracture process can
be measured quite well using high-frequency data processing system. It is also revealed that the instant fracture of structural
connection is characterized by progressive and partial fracture. Numerical evaluation of the impact effect of connection fracture
is carried out.
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Translated from Journal of Tongji University (Natural Science), 2007, 35(3): 299–303, 314 [译自: 同济大学学报(自然科学版)] 相似文献
19.
Chen Changfu Xiao Shujun Yang Yu 《Frontiers of Architecture and Civil Engineering in China》2007,1(3):329-333
Based on the unified strength theory [1], a unified strength criterion for strain softening materials, such as concrete or
rock, was derived, and the elastic and plastic limit loads of a thick-walled cylinder made of these materials subject to external
pressure were also given. In addition, the influence of some factors on the limit loads of such cylinders as the ratio of
the external radius to internal radius, r
b/r
a, the coefficient b, which reflects the effect of medium principal stress and the normal stress of the relevant surface on the material destroy
degree, the ratio of tensile strength to compressed strength of the material, α, and the damage variable β were discussed
in detail. Some examples were given and some meaningful results were obtained.
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Translated from Journal of Hunan University (Natural Science), 2006, 33(2): 1–5 [译自: 湖南大学学报 (自然科学版)] 相似文献
20.
Fuyou Xu Airong Chen Zhe Zhang Cailiang Huang 《Frontiers of Architecture and Civil Engineering in China》2009,3(3):272-278
The causes of the nonlinearity of self-excited aerodynamic force of bridge are interpreted from such two aspects as amplitude
and wind velocity. The concept of “generalized flutter derivative” is proposed, and its physical meaning is illustrated. The
graphs of the generalized flutter derivatives of plate and Sutong Bridge section model are plotted. The characteristics of
all generalized flutter derivatives are compared and analyzed, and their superiorities are verified. The results indicate
that the physical meaning of generalized flutter derivatives are more explicit compared to the traditional ones. It is more
convenient to understand the nonlinearity properties of self-excited aerodynamic force of bridge according to the generalized
flutter derivatives graphs with the wind velocity as the horizontal coordinate.
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Translated from Journal of Wuhan University of Technology (Transportation Science and Engineering), 2008, 32(4): 607–610 [译自: 武汉理工大学学报(交通科学与工程版)] 相似文献