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Wei E.,Wuhan University | Shi Q.,Tianjin Geo Engineering Investigation Institute | Yan W.,Wuhan University | Li X.,Wuhan University
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University | Year: 2011

The differential VLBI model used for Lunar probe positioning is derived. CE-1's data is used to estimating ERP as well as positioning. The results show that: (1) The ERP's precision has a great influence to the probe positioning accuracy, and the increasing of ERP accuracy can help to improve the positioning accuracy of the probe. (2) The ERP's precision can be improved by estimating probe's position and ERP parameters simultaneously with the ΔDOR observations between the CE-1 Lunar probe and a reference radio source. Source


Jiang Y.,Tianjin University | Lei H.-Y.,Tianjin University | Zheng G.,Tianjin University | Yang X.-J.,Tianjin Geo Engineering Investigation Institute
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2011

In order to analyze the deformation characteristics of structured soft clay in Tianjin Binhai New Aera, dynamic triaxial test was conducted under traffic load, soil structure's yield pressure was considered based on the disturbed state concept, a disturbed function was put forward which considered the gradual destruction of soil structure under cyclic load, an empirical formula of plastic deformation was proposed and vertified by using the test. Analysis result shows that the relationship between accumulative plastic strain and cyclic number under cyclic load is divided into stable type and destroyed type. Accumulative plastic strain increases with the increase of cyclic number. There exists a critical cyclic stress ratio under the same confining pressure. The maximum of critical cyclic stress ratio decreases with the increase of confining pressure. Obviously, the empirical formula reflects the deformation characteristics of soil under traffic loadi. Source


Gong H.,Tianjin Geo Engineering Investigation Institute | Zhu C.,CAS Institute of Geology and Geophysics | Xu M.,CAS Institute of Geology and Geophysics | Guo T.,Sinopec | And 3 more authors.
Scientia Geologica Sinica | Year: 2010

The temperature logging curve of Dingshan 1 shows that as the depth goes to higher the temperature rising, the value is 25°C at the top, and 107.5°C at the bottom. The temperature logging curve has an "arch" at the depth of 1000~3000 m. The observational temperature gradient section can be divided to 3 parts;its value of the Permian strata is 23.94°C/km, and its value of Silurian and Ordovician is 37.27°C/km, while the temperature gradient is very low, the value is 16.65°C/km. According to the characteristic of geothermal gradient section and its relationships and pertinences with the thermal conductivities and lithology of the stratum, we reach a conclusion that the vertical motion of subsurface fluid caused the perturbation of the temperature curve. This conclusion is adopted to deduce the strata of Cambrian have high porosity and permeability, while the strata of Silurian-Ordovician have a high sealing capacity, and this assembly of strata is propitious to the hydrocarbon's accumulation. It may be an indication of that there is a potential of the 'Lower Assemblage' in south-east Sichuan Basin. Source


Wei E.,Wuhan University | Shi Q.,Tianjin Geo Engineering Investigation Institute | Liu J.,Wuhan University | Li X.,Wuhan University | And 2 more authors.
2011 International Conference on Electronics, Communications and Control, ICECC 2011 - Proceedings | Year: 2011

In this paper, differential VLBI ( VLBI) model used for Chang'e-1 (CE-1) Transfer Orbit positioning is derived Based on the model, error equation of observations is formed and coefficient matrix A is designed Finally the influence of predicted accuracy of ERPs on CE-1 positioning accuracy is analyzed and some results are given © 2011 IEEE. Source


Jiang Y.,Tianjin University | Lei H.-Y.,Tianjin University | Zheng G.,Tianjin University | Yang X.-J.,Tianjin Geo Engineering Investigation Institute
Yantu Lixue/Rock and Soil Mechanics | Year: 2010

In order to understand the dynamic characteristics of the structured soft soil in Tianjin Binhai Area, dynamic triaxial test and mercury intrusion test are applied to measure microscopic features of structured clay. The microstructures of unloaded and loaded soft soils are studied by means of the mercury intrusion tests. The fractal theory is used and the fractal characteristics of pore distribution are studied through the data analysis. The method of pore classification is proposed; and the relationship between porosity feature and excellent frequency are formulated. The results indicate that the pore of structured clays under traffic loading is able to be divided into three types according to relation curve of pore diameter and volume of the structured clays. Menger sponge model can be applied to fractal research of the pore characteristics of structured clays under traffic loading. The porosity fractal dimension can be employed for predicting the excellent frequency and analyzing soil deformation mechanism under the embankment. Source

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