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Zhu S.,Hohai University | Wang Y.,Hohai University | Weng H.,Hohai University | Weng H.,Hongrun Construction Group Co.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

The scale effect of density on the mechanical properties of coarse-grained dam materials is ignored in previous studies. On this basis, four scale methods are used to obtain the maximum dry density in laboratory according to the original average design gradation curve of rockfill in Shuangjiangkou earth-rockfill dam. Based on the design generatrix of the coarse-grained dam materials gradation-Talbot curve and fractal geometry theory, the mechanism of scale effect of density for coarse-grained dam materials is interpreted, which selects the Talbot formula index and the factor reflecting the particle shape and roughness as the fractal indices. The basis of quantitatively evaluating the effect of gradation on density is provided; and the shortcomings of fuzzy evaluation only using the non-uniformity coefficient and curvature coefficient is overcome. Combined the mixed scale method, the numerical tests on the maximum dry density is carried out by using the particle flow code in two dimensions(PFC2D); the law of scale effect on the relative density and porosity of coarse-grained materials is studied; and the microscopic mechanism causing the difference is analyzed. Source

Bao X.-F.,Hongrun Construction Group Co. | Ge X.,Shanghai Municipal Engineering Design General Institute | Wang H.,Shanghai Municipal Engineering Design General Institute | Wu F.,Shanghai Municipal Engineering Design General Institute
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

The excavation of Expo axis is about 1000 m in length and 100 m in width, divided into three parts according to the excavation depth. The 800 mm diaphragm wall with slope or cement-soil wall combined top-downwards basement construction with partial floors used as horizontal frame is used in B2 part with the excavation depth 12 m and the protection level 3; The 1000 mm diaphragm wall with slope or cement-soil is used in shallow B3 part with the excavation depth 17 m and the construction method is similar to that of B2 part; The 1000 mm diaphragm wall combined with top-downwards basement construction is used in deep B3 part with the excavation depth 21.5 m and the protection level 2. The field measured results are shown also. The problem of large excavation is solved economically and safely. Source

Zhu J.-G.,Hohai University | Liu Z.,Hohai University | Weng H.-Y.,Hongrun Construction Group Co. | Wu Z.-F.,Hohai University | Fu H.-Y.,Hohai University
Sichuan Daxue Xuebao (Gongcheng Kexue Ban)/Journal of Sichuan University (Engineering Science Edition) | Year: 2012

The conventional consolidated drained triaxial compression tests with three specimen dimensions were performed, and difference of the stress-strain behavior and shear strength between specimens at different sizes of a coarse-grained soil were investigated. The effect of specimen size on the behavior was studied. The test results showed that the stress-strain relation and the dilatancy for specimens with different size exhibit similar behavior, and the value is different. For the soil with the same cell pressure and gradation, the peak deviatoric stress of smaller specimen is higher than that of larger specimen, and the difference of the peak deviatoric stress decreases with the increase of specimen size. At lower cell pressure, variation of specimen size induces larger change of friction angle, and at higher pressure, the effect of specimen size on the angle becomes small. The Young's modulus and bulk modulus also change with the specimen size, and the law is to be verified by more test results. Source

Zhu H.,Tongji University | Liu X.,Hongrun Construction Group Co. | Yao X.,Tongji University
Advanced Materials Research | Year: 2012

Based on the engineering that shield machine's passing through a vertical shaft in urban rail transit construction, two methods are proposed according to the engineering geology and construction organization and finite element model is established to simulate the real situation. After the technical analysis and safety analysis of the two methods, the recommended method is given, also given are the corresponding safety measures and construction procedure. The success of this engineering proves that this analysis is reasonable and the safety measures are worth of referring to. © (2012) Trans Tech Publications, Switzerland. Source

Yuan Y.,Tongji University | Takao U.,Tokushima University | Yu C.,Hongrun Construction Group Co.
Advanced Materials Research | Year: 2012

The major content in concrete is aggregates. Reduce its usage and replaced with recycled concrete aggregate (RCA) could not only mitigate consuming of natural resources but avoid the treatment of solid wastes. Furthermore, producing self-compacting concrete (SCC) with RCA is a way for traditional construction industry in saving energy and avoiding noise emission. To seek the proper way in preparation of SCC with RCA, preparation of RCA, composition design, microstructure evolution with hydration, and mechanical properties are investigated within this study. It is found that successful producing of SCC with RCA is not a complicated process. © (2012) Trans Tech Publications, Switzerland. Source

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