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Zhang G.,Tsinghua University | Hu Y.,East China Architectural Design and Research Institute Co
International Journal of Geomechanics | Year: 2017

A finite-element analysis program was developed to analyze the progressive failure of a soil slope based on the progressive failure mechanism. The shear element was developed to comprehensively characterize the shear zone, which describes the soil shear deformation localization of progressive failure. The formulation of the shear element was derived using a format similar to that of the soil-structure interface element and incorporated into the traditional FEM to macroscopically simulate the deformation and failure processes of the slope. A series of algorithms, including the combination and transformation of the shear element and the entity element, were proposed to obtain the full solutions for the progressive failure of soil slopes. The simulation results using the developed program for the slip surface, failure process, and displacement distribution match the observations of centrifuge model tests well. © 2016 American Society of Civil Engineers.


Wang J.H.,Shanghai JiaoTong University | Xu Z.H.,East China Architectural Design and Research Institute Co. | Wang W.D.,East China Architectural Design and Research Institute Co.
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2010

An extensive database of 300 case histories of wall displacements and ground settlements due to deep excavations in Shanghai soft soils were collected and analyzed. The mean values of the maximum lateral displacements of walls constructed by the top-down method, walls constructed by the bottom-up method (including diaphragm walls, contiguous pile walls, and compound deep soil mixing walls), sheet pile walls, compound soil nail walls, and deep soil mixing walls are 0.27%H, 0.4%H, 1.5%H, 0.55%H, and 0.91%H, respectively, where H is the excavation depth. The mean value of the maximum ground surface settlement is 0.42%H. The settlement influence zone reaches to a distance of about 1.5H to 3.5H from the excavation. The ratio between the maximum ground surface settlement and the maximum lateral displacement of a wall generally ranges from 0.4 to 2.0, with an average value of 0.9. The factors affecting the deformation of the wall were analyzed. It shows that there is a slight evidence of a trend for decreasing wall displacement with increasing system stiffness and the factor of safety against basal heave. Wall and ground movements were also compared with that observed in worldwide case histories. © 2010 ASCE.


Huang M.,Tongji University | Wang W.,East China Architectural Design and Research Institute Co. | Zheng G.,Tianjin University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2012

The status of the research on underground engineering in soft soils are reviewed. Three types of key issues in deep excavations and shield tunnelling are discussed. The first one is concerned with the new methods and technilogies for deep excavations in soft soils under complicated geological and environmental conditions, such as the stress analysis of retaining structures for foundation pits, basal stability analysis of excavations, the influence of seepage on the stability of deep excavation, the redundancy of deep excavations, and the new technique of excavations in soft soils. The second one focuses on the stability and deformation analysis of tunnel in soft soils, including the stability analysis of tunnel face, the influence of seepage on the stability, the longitudinal differential settlement and the long-term settlement of tunnel, theoretical analysis and model test of the seismic response of tunnel. The last one involves the ground deformation induced by deep excavation and tunneling, and the environmental influences from underground construction.


Wang W.-D.,Tongji University | Wang W.-D.,East China Architectural Design and Research Institute Co. | Wang H.-R.,Tongji University | Xu Z.-H.,East China Architectural Design and Research Institute Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2012

The hardening soil model has become one of the most widely used constitutive models in numerical analysis of excavations. The key issue of numerical analysis using hardening soil model is determining parameters of this model. Soil samples of typical soil layers ((2) 2, (3), (4) and (5) 3) in Shanghai soft deposit is got by using thin wall samplers. The stress-strain curves of soil is got through triaxial consolidated drained test and triaxial loading-unloading-reloading drained test based on GDS and the load-strain curve of soil is got through consolidation test. Parameters of the hardening soil model are determined according to the test results. At the same time, relationships betweenE oed ref, E 50 ref, E ur ref and E s1-2 are established. The parameters and these relationships are also compared with those of soils in other districts. The test results can be used as references for numerical analysis of excavations in Shanghai and other soft soil districts.


Yu Z.,East China Architectural Design and Research Institute Co.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2010

The main structure of the World Expo Cultural Center consists of 36 cantilever trusses of varying span and inner frames. Static load is the primary load case of such a structure. Effective control of the deformation of the end of truss and reduction of the force of the truss and inner frame are the focus during the structural design. The load bearing feature of the structure was analyzed and the key components was strengthened correspondingly. Firstly, two circumferential frame beams on the top of the column were designed with steel rectangular tube; secondly, slab of the sixth floor was thickened to 200mm and steel plate was welded between the first panel of the cantilever truss. These measures put a 'tight restriction' on the top of 36 cantilever trusses and significantly reduced the deformation of the end of truss and the force of main members. Dynamic analysis shows that the vibration characteristics of the structure are different from normal tall buildings. As for this structure, torsion is the first modal shape, but lateral stiffness of the structure is very strong, lateral force resisting components are evenly distributed and the frame is made of steel so that brittle failure is not easy to occur when the structure suffering horizontal earthquake. In order to study the influence of floor stiffness, three models of calculating real floor stiffness, without floor stiffness and only single frame were respectively analyzed and the differences of the force of main components were studied in details. The results indicate that floor stiffness has a significant influence on the force of main members but the influence is different. So that the envelope results of the above three models are all considered during the design course.


Wang D.,East China Architectural Design and Research Institute Co. | Zhou J.,East China Architectural Design and Research Institute Co.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2010

Hybrid high-rise building structure has both the advantages of steel structure and concrete structure. Steel and concrete hybrid structures are widely used in China in recent years. However, different views exist related to the seismic behavior of hybrid structures and key design methodologies. This paper attempts to summarize various hybrid structure systems along with introduction of typical engineering examples. Key technical issues are discussed, including seismic behavior, ductility design, member design, the reliability of connections, difference in vertical deformation, construction analysis, nonlinear time-history analysis and damping ratio. Future research needs are also suggested.


Yi J.,East China Architectural Design and Research Institute Co.
Advanced Materials Research | Year: 2012

For the sake of studying on the thermal effects of glass curtain-wall to the integrated buildings, 16 types of glass curtain wall are slected to build office building energy consumption models, and the meteorologic parameters are chosed from Harbin, Beijing, Shanghai and Guangzhou respectively, totally 384 models are investigated. The simulation results show that, U-value of glass curtain-wall impacts less to the energy consumpiton of intergrated building from the northern city as Harbin to the southern city as Guangzhou, the SC of glass curtain-wall has a stronger impact on the energy consumpiton of intergrated building from the north to the south of China, which is reverse effect of the U value. © (2012) Trans Tech Publications, Switzerland.


Wang W.-D.,East China Architectural Design and Research Institute Co. | Xu Z.-H.,East China Architectural Design and Research Institute Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

A simplified analysis method is proposed to evaluate excavation-induced damage of buildings. Firstly, the method of predicting ground surface settlement profile is proposed based on a large number of monitored data of deep excavations in Shanghai soft ground. It is proved that this method is suitable for estimating ground surface settlement. Secondly, a calculation method of additional deformation of adjacent buildings is proposed. Thirdly, the criteria are proposed for evaluating damage of buildings according to angular distortion. A case history is presented to illustrate the detailed procedures of adopting the simplified analysis method. It is shown that the results obtained by the simplified analysis method agree with the monitoring data.


Liu R.-B.,East China Architectural Design and Research Institute Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2012

The Shanghai Caoxi Road Station Plot Public Open Space Project is located in the downtown of Shanghai City. The excavation is adjacent to several city roads, pipelines, elevated road, light rail line and station. Protection requirements of the surrounding facilities are quite high, especially for the large-diameter sewage pipes at the north side of the excavation. The general situation of the project and the overall design scheme of the deep excavation are introduced. Emphasis is put on the technical countermeasures of protecting the large-diameter sewage pipes, including constructing the bored piles in the cement mixing soil, using elevated soil conveying path, and tracing grouting. The monitoring results show that the surrounding environments are effectively protected by the adopted supporting system and technical countermeasures. The successful construction of the deep excavation creats favorable conditions for the construction of the main structures of the project.


Xu Z.-H.,East China Architectural Design and Research Institute Co. | Wang W.-D.,East China Architectural Design and Research Institute Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2010

Numerical analysis has become the most important method for analyzing deep excavations in close proximity to sensitive properties. One of the key problems in a numerical analysis is to select proper soil constitutive models and their corresponding parameters. The possibilities and limitations of a limited number of soil constitutive models frequently used in geotechnical numerical simulations were discussed. The suitability of these constitutive models applied to numerical analysis of deep excavations in close proximity to sensitive properties was compared. As ground movement control is a key design consideration in excavations adjacent to sensitive properties, the constitutive model must be able to predict realistic distributions of movement around retaining structures. It was recommended to use strain hardening plastic constitutive models such as modified Cam clay (MCC) model and Plaxis Hardening Soil (HS) model to simulate excavations in close proximity to sensitive properties because they can reflect many important features of soil which are important in excavation simulations. These features include plasticity, strain hardening difference between loading and unloading stiffness, and stress dependent stiffness. The results of the simulation of a deep excavation illustrate the capabilities of the strain hardening plastic constitutive model in the numerical analysis of deep excavations.

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