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The 5th Cross-strait Conference on Structural and Geotechnical Engineering (SGE-5) Hong Kong, China, 13-15 July 2011 RECENT SEISMIC DESIGN AND RETROFIT STUDIES OF BRIDGES AT NCREE ABSTRACT K. C. Chang 1,2 , H. H. Hung 1 and K. Y. Liu 1 1 National Center for Research on Earthquake Engineering, Taipei, Taiwan 2 Department of Civil Engineering, National Taiwan University Email: kcchang@ncree.narl.org.tw Taiwan is located in a highly seismic active region of the world. Therefore, the structures in Taiwan suffer frequently from earthquakes. Over the years, several earthquake events not only damaged the structures and caused life and property losses, but also impeded the economic development of the country. As such, the seismic design and retrofit of structures have become an essential issue for the sustainable development of Taiwan. As part of this, the National Center for Research on Earthquake Engineering (NCREE) was officially established in Taiwan in 1990. Thsis paper will introduce the researches at NCREE related to seismic design and retrofit of bridges in recent years. These studies to be presented include the seismic retrofitting program, the rocking behavior of bridge column with spread footing, and an on-site experiment of three bridge columns performed in last year. KEYWORDS FRP, RC beams, strengthening, interfacial stresses, analytical solution. INTRODUCTION Taiwan is located along the western ridge of the Pacific Ocean earthquake belt and thus suffers frequently from earthquakes. Frequent earthquakes have inevitably caused significant damages to the existing bridges in Taiwan. The damages of the bridges due to earthquake not only lead to the loss of many innocent lives, but also interfere with the rescue efforts, generating countless amount of cost to the society and economy. These circumstances lead special attention to be given to seismic design and retrofit in Taiwan, especially after the devastating Chi-Chi earthquake occurred in the central part of Taiwan on September 21, 1999. The National Center for Research on Earthquake Engineering (NCREE) in Taiwan, which was officially established in 1990, has continued to bring together academic resources and researchers to carry out joint projects to upgrade seismic design and retrofit technologies to reduce life and property losses resulting from earthquake in the recently two decades. This paper will introduce some latest researches at NCREE related to seismic design and retrofit of bridges. These studies to be presented include a coordinated research program related to the seismic retrofitting of RC bridge columns, two series of experiments focused on the rocking behavior of bridge column with spread footing, and an on-site experiment of three bridge columns performed in last year. SEISMIC RETROFIT STUDY OF RC BRIDGE COLUMNS Background and Objectives Significant amount of retrofit research and actual implementations to enhance the seismic performance of existing bridges have been made in the United States, Japan and New Zealand after some major earthquakes occurred in these countries. In order to make sure that if the retrofit methods used in these countries were also effective for the existing RC bridge columns in Taiwan, a 4-years coordinated research effort on seismic retrofit of existing RC bridge columns were established at the NCREE from 1998 to 2002. Major objectives of this program were to develop effective seismic retrofit methods of existing bridges in Taiwan due to (1) inadequate design strength, (2) inadequate confinement at potential plastic hinge region, (3) inadequate shear strength due to large lateral steel spacing, and (4) lap-splicing in the plastic hinge zone. This coordinated research program includes a master plan administrated by NCREE and seven coordinated projects handled by the investigators from six universities and research institutions. The joint research effort has applied several retrofit techniques in the tests, including the steel jacketing, reinforced concrete jacketing, and the advanced composite material wrapping using the FRP. Results of this research program provided a domestic test database for seismic bridge engineering applications and seismic retrofit guidelines for highway officials in Taiwan. -106-
Experimental Program More than 60 large scale specimens were tested, including 24 benchmark specimens that were designed to represent typical pre- and after 1987 bridge columns in Taiwan. Cross sectional dimensions of the rectangular columns and circular columns were 60 cm by 75 cm and 76 cm diameter, respectively, roughly 2/5 scale of the prototype columns. Retrofit techniques used in the specimens include steel jacketing, FRP wrapping, and RC jacketing. Details of the test specimens are listed in Tables 1-3. Failure type Flexural Shear Lap-spli ces Table 1 Detail of benchmark specimens Specimen Cross section Height Axial load Longitudinal Reinforcement Transverse Reinforcement Arrange Cut off Arrangement -ment height PHZ Non-PHZ (mm) (mm) (f'c Ag) (mm) (mm) (mm) (mm) BMR1 750*600 3250 0.1 32-19Φ --- 9Φ@100 9Φ@100 BMR2 750*600 3250 0.1 32-16Φ 1800 9Φ@130 9Φ@240 BMR3 750*600 3250 0.15 32-16Φ 1800 9Φ@130 9Φ@240 BMR4 750*600 3250 0.15 32-16Φ 1800 9Φ@230 9Φ@230 BMR1-R 750*600 3250 0.15 34-19Φ 1800 9Φ@100 9Φ@100 BMC1 D=760 3250 0.15 34-19Φ --- 9Φ@70 9Φ@100 BMC2 D=760 3250 0.15 30-16Φ 1800 9Φ@130 9Φ@220 BMC3 D=760 3250 0.15 30-16Φ 1800 9Φ@230 9Φ@230 BMC4 D=760 3250 0.15 30-17Φ 1800 9Φ@130 9Φ@220 SC1 D=760 3250 0.15 26-16Φ 1250 9Φ@140 9Φ@240 SC1-R D=760 3250 0.15 26-16Φ 1250 9Φ@140 9Φ@240 FC1 D=750 3250 0.15 32-16Φ --- 9Φ@100 9Φ@100 FC4 D=750 3250 0.15 18-16Φ --- 9Φ@300 9Φ@300 BMRS 750*600 1750 0.15 30-19Φ --- 9Φ@300 9Φ@300 BMCS D=760 1750 0.15 30-19Φ --- 9Φ@300 9Φ@300 BMRL100 750*600 3250 0.15 30-19Φ 760 9Φ@130 9Φ@220 BMRL50 750*600 3250 0.15 30-19Φ 760 9Φ@130 9Φ@220 BMCL100 D=760 3250 0.15 30-19Φ 760 9Φ@130 9Φ@220 BMCL50 750*600 3250 0.15 30-19Φ 760 9Φ@130 9Φ@220 Table 2 Retrofit methods of rectangular specimens Failure Type Flexural Shear Lap splices Retrofit/Repair Benchmark Note Spec men FR1 BMR2 FRP(8 layers) FR2 B R3 FRP(4 layers) SR1 Large octagon SR2 Ellipse SR3 Small octagon S 4 Ellipse FRS BMRS FRP(4 layers) SRS1 Small octagon SRS2 Ellipse BMRS-RC RC(9cm) FRL 100 BMRL 100 FRP(8 layers) SFRL 100 Steel+FRP SRL1 Small octagon SRL2 Ellipse BMRL 100-RC RC(9cm) BMRL 50-RC BMRL 50 RC(9cm) Table 3 Retrofit methods of circular specimens Failure type Flexural Shear Lap splices Retrofit/repair Benchmark Note specimen SC2 SC1 Steel(3mm) SC3 BNC2 Steel(3mm) FC2 FC2 FRP(4 layers) FC3 FRP(4 layers) RCC2 BMC2 RC(9 cm) BMC4-RC BMC4 RC(9 cm) SCS BMCS Steel(3mm) FCS FRP(4 Layers) FCS-1 FRP(3 Layers) FCS-2 FRP(2 Layers) FCS-3 High pressure Epoxy injected SCL 100 BMCL 100 Steel(3mm) FCL 100 FRP (6-2layers) FCL 100-1 FRP (4-2layers) FCL 100-2 FRP (6-2layers) FCL 100-3 FRP (6-2layers) RCCL1 RC(9cm) RCCL2 RC(9cm) BMCL50-RC BMCL 50 RC(9cm) Test Results and Conclusions For seismic retrofit of rectangular RC bridge columns using steel jacketing and FRP wrapping, the hysteresis loop of the columns are shown in Fig. 1 (Tsai and Lin 2000) and Fig. 2 (Chang and Chung 2000; Chang and Chang 2000), respectively. Test results for Fig. 1 confirmed that the seismic performance of the rectangular RC bridge columns can be significantly and equally enhanced by properly constructed elliptical or octagonal steel jacket. Octagonal steel jacketing is cost-effectively and can provide lateral confinement and the shear strength to -107-
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Proceedings of the 5th Cross-strait
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SCIENTIFIC COMMITTEE Chairman Jan-M
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ORGANIZING COMMITTEE Co-chairmen Yi
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设计大师金问鲁教授
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TABLE OF CONTENTS Scientific Commit
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J.T. Shi & L. Su Impact of Spatial
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Temperature Effect on Variation of
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Trace Analysis of Mechanical Respon
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Keynote Lectures
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图 1 海峡大桥三个路
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非主通航孔的跨径应
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The 5th Cross-strait Conference on
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图 3 空间结构按单元
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图 7 多面体空间框架
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图 14 内蒙古响沙湾沙
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5.3. MRF3 索穹顶 — 网壳
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图 29 杭州黄龙体育中
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(a) 鸟瞰图 (b) 计算模型
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As it is conventional, the displace
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⎡ n n ⎤ ⎢q 1 0( z− Li) q0(
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frequencies of interest and the tra
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Another phenomenon observed from Fi
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刚塑性平面应变极限
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采用数值极限分析法
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为了推测浅埋隧洞破
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鹤梁岩壁面上至今已
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图 6 黄庭坚题铭 “ 元
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图 16 巫山神女图 17 长
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五、历年来研究过的
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在会议结束前给我半
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图 31 院士建议文件的
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科所、重庆交通学院
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图 37 白鹤梁题刻中段
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图 46 上下游水平交通
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图 59 参观廊道安装在
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Page 88 and 89: The 5th Cross-strait Conference on
Page 90 and 91: (a) 模型 I (b) 模型 II (c)
Page 92 and 93: (a) 水平接缝处螺钉松
Page 94 and 95: 表 5 模型 I 在 9 度罕遇
Page 98 and 99: 1.2. 大型钢结构设计
Page 100 and 101: 5250 5000 i= 0.07 1 i= 0.07 5000 16
Page 102 and 103: A Pb Pa Pb A Pb Pa Pb Pa Pa ax Pb P
Page 104 and 105: (a) 预应力索布置 (b) 1/6
Page 106 and 107: 图 23 150m×150m 周边简支
Page 108 and 109: 图 27(a) 自重作用下结
Page 110: 四、结语 150m×150m 空间
Page 115 and 116: 通过上述技术创新平
Page 119 and 120: * θt r1cosθ r2cosθ2 = = (9) * 1
Page 121 and 122: 圖 10 水平軌枕方向之
Page 123 and 124: 圖 19 水平軌枕方向之
Page 125: 向量 r r &r r 的變化率
Page 129 and 130: failure mode specimens, applying CF
Page 131 and 132: columns were reinforced with three
Page 133 and 134: e formed at the column base and the
Page 135 and 136: Acceleration (g) 1 0.5 0 -0.5 Simul
Page 139 and 140: Table 2 Mix Proportion of the PDCC
Page 141 and 142: observed between the formwork and c
Page 143 and 144: In the above example, the GFRP with
Page 145 and 146: 构的加固修复 , 二是
Page 147 and 148: FRP 网格 FRP 筋和索 FRP 布
Page 149 and 150: (2) 钢筋 - 连续纤维复
Page 151 and 152: 生退化。拉伸强度相
Page 153 and 154: 图 16 两种纤维混杂增
Page 155 and 156: σ tf 混凝土构件粘结
Page 157 and 158: 新型抗震结构的荷载
Page 159 and 160: 的破坏过程也与柱 C-S
Page 161 and 162: 拉索频率阶数也低于
Page 163 and 164: A m plitude (m m ) 6000 5000 4000 3
Page 165 and 166: 产工艺进行探索性研
Page 167 and 168: Girders with Externally Prestressed
Page 169 and 170: concrete columns were documented by
Page 171 and 172: fatigue life of steel columns. Xiao
Page 173 and 174: Figure 11 Relationships between res
Page 175 and 176: 20. Xiao, Y. and Wu, H. (2000). “
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phenomenon, however, cannot be cons
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ase rock; H j ( iω) , H k ( iω) a
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For the coherency loss function bet
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Numerical Results The earthquake-in
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REFERENCES Bi, K., Hao, H. and Ren,
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Figure 3 Idealised bonded joint mod
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A = 0 1 (6a) B1 = −δ f (6b) f si
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Table 1 Test and predicted flexural
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COMPARISON OF FLEXURAL DEBONDING MO
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Figure 2 Location of smart aggregat
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Figure 5 Experimental setup Figure
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Figure 15 Impact location on FRP wr
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REFERENCES Bhalla, S. and Soh, C.K.
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The RVE, occupying a geometrical do
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[ ut ] is the tangential vector if
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extended to the resolution of the n
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469.1m,f m =55%,f I =45% -50 Σ 3 -
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頭混凝土護蓋敲除 ,
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發生夾片咬合失敗 ,
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會因設計長度不足 ,
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面之反推分析可知 ,
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因此連擋土牆本身之
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⎛τ ⎞ av ⎛amax ⎞⎛σ ⎞ v
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地液化与否初步判别
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等 (2000) [15] 在试验中都
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五、结论剪切波速法
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钢混凝土相当于将型
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A g — 混凝土毛截面面
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5.1. 大连市体育馆钢
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土梁中设立直线预应
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混凝土板外侧 , 受力
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试验采用跨中两点对
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为了深入了解槽型钢
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笔者针对已有结合部
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面 , 浇注的混凝土和
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(c) 波形钢腹板工字型
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manner for statistical analysis, (i
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3.3.1 Software System for Instrumen
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spectrum is obtained in an approxim
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e carried out once per maintenance
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The monitoring work is composed of
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displacement influence lines and st
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efers to data processing and storag
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Hong Kong Institution of Engineers.
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Monitoring Category Bridge Features
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9 Combination of Above Divided Sect
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Back to Routine Monitoring Not Exce
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Tsing Yi Stonecutters Figure 5 Layo
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Continuous Data Acquisition GPS Tim
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Y(+ve) Y T Temperature Distribution
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Type of Input Data Type of Data Pro
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Tsing Yi Stonecutters Stonecutters
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青衣 Tsing Yi 昂船洲 Stonec
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Accelerometer Fixing of Portable Ac
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Tsing Yi Stonecutters Bridge Stonec
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Structural Health Data Management S
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a mean recurrence interval with ext
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The present study is concerned with
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which all the variables have the sa
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450 35 400 30 350 300 25 ( 1.0E- 6)
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Structural Engineering and Mechanic
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provided in DBELA, a base rotation
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ξ ( μ − ) 3 eq −ξ0 = C + D 1
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equivalent displacements exceed the
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Displacement (cm) 70 60 50 40 30 20
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it give rather reasonable results,
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RANDOM FIELD AND SPATIAL AVERAGING
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satisfactorily when SOF is large bu
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those of the average shear strength
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then rinsed three times with deioni
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The Freundlich model can be express
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Ministry of Education for their fin
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United States.) The available site
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ACKNOWLEDGMENTS Financial support f
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the author has quoted the outdated
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Figure 5 The geological map of 2000
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Figure 11 Rock cores of vent brecci
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Due to the misidentification of roc
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ACKNOWLEDGEMENT The author would of
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Recently, as the development of fin
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( x ) ( x ) L m ( x ) ( x ) ( x ) L
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Step1: initializing the nonlinear o
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Table 1 The results of limit load m
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Khosravifard, A., Hematiyan, M.R. (
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阿坝州没有水库 , 凉
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汶川地震中属于溃坝
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缝宽约 2mm~5mm; 纵向断
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Problem with Seismic Hazard Analysi
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INADEQUACY OF TSUNAMI MITIGATION ST
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demonstrated that huge earthquake c
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三、粮库室内地面沉
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土层的物理力学参数
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笔者对 4# 粮库的沉降
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二国标中主动土压力
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表 3 c =0kPa 时不同的 δ
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的值比公式 (1) 的值小
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[1] 究等方面都有了新
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(3) 根据对隧道典型断
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水平收敛位移 (mm) 12.00
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THREE PROCEDURES FOR SCALING GROUND
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Peak displacement (m) 84, 50, 16 pe
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CONCLUSIONS Performance-based desig
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Figure 3 Physical diagrams of pile
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load-deflection curve at the pile h
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在此选取 Kondner [10] 及 Go
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及附加内力的简单方
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The dual is min * w, b, ξξ , s.t
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Table 1 The results of example 1 Re
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P P P P P P P P P P P P 4 5 4 A 2 4
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Figure 2 is a photograph of the int
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SHAKING TABLE TEST PROGRAM System i
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Force (N) 600 500 400 300 200 100 N
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Figure 9 Comparison of SAF-TMD and
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鋼線 , 近期更發展為
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三、吊橋基本資料表
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底端固定型式 □ 夾具
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4.2.3 吊橋扭轉行為之
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由式 (11)~(13) 可求得闭
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3.2 脉动风压时程结构
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4.2 主动控制力分析图
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egarded as a serviceability limit s
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observed that the measured values c
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_ Cumulative Frequency of Samples (
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三个项目基本概况对
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风作用下基底总 X 向 7
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主要技术指标对比表
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六、上部结构材料用
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m 2 , 三个项目采用混
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STADIUM ROOF BRIEF Jaber Al-Ahmad I
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a) 1st modal shape Figure.7 Modal s
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1) 所需的机具设备少
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6.1. 挠度选取典型加
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七、结论通过上述研
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where c = cope length,D = beam dept
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A post-ultimate stiffness of 200 MP
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Table 3 Summary of the variables of
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Effects of Web Slenderness (d/t w )
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REFERENCES ABAQUS/Standard User’s
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规程 [7]。文献 [2]、[3]
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为探究球节点壁厚对
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[4] 王星 , 董石麟 , 完海
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一、前言鋼纜為斜張
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圖 1 愛蘭矮塔斜張橋
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態頻率後 , 由圖 6 可清
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素連接 , 假設兩構件
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图 3 半片梁的有限元
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加固前的钢筋混凝土
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and a corresponding shear strain of
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对温度变化效应进行
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典型节点 : 在钢结构
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钢结构第一阶振型为
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(a) 上支座节点 (b) 下支
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上部屋面钢结构下部
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验算 4、6 号线重力荷
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采用 SAP2000, 对各种截
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高屏溪引橋共包含五
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表 3 由高屏溪斜張橋
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圖 7 垂直撓曲第一振
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表 7 在 P2 橋墩不同沖
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