Xu Y.,Fujian Agriculture and forestry University |
Liu H.,Wuhan University |
Zhang Y.,Surveying and Mapping Engineering in Shanxi Province |
Feng Y.,Shandong Provincial Institute of Land Surveying and Mapping
Lecture Notes in Electrical Engineering | Year: 2012
The observations of Tianjin Continuously Operating Reference System (TJCORS) of 2007-2009 are calculated by BERNESE 5.0 Software. Then the position site time series from all of the reference stations are obtained, which are analyzed from aspects of periodicity, noise and tendency to figure out the time series' features and the movement tendency of TJCORS. The periodicity analysis shows that the 3 coordinate components (N, E, U) have semi-annual and annual periodicity, and the periodicity of U direction is more obvious than that of the other two. The model of "white noise + flicker noise" is preferred to describe the reference station noise series according to the noise analysis. Then the movement of TJCORS is discussed. TJCORS has a movement tendency towards southeast horizontally. The vertical displacement velocity of the 12 stations is from -0.05 to -41.29 mm/a. In the end, the results of TJCORS and the leveling are compared to prove that the former results are of accuracy. The comparison shows that the vertical displacements gained by the two methods are identical. © 2012 Springer-Verlag GmbH.
Li J.,China University of Geosciences |
Yuan G.-L.,China University of Geosciences |
Deng X.-R.,Shandong Provincial Institute of Land Surveying and Mapping |
Jing X.-M.,China University of Geosciences |
And 3 more authors.
Environmental Earth Sciences | Year: 2016
To explore the chemical weathering processes and the anthropogenic disturbance of weathering, 20 water samples were collected from the tributaries in the Nansihu Lake basin, a growing industrial area. The major ions in river waters were analyzed to identify and quantify the contributions of the different reservoirs. Based on stoichiometric analyses and end-member determination, the contributions of individual reservoirs were calculated for each tributary. In the study region, the averaged contributions of atmospheric inputs, anthropogenic inputs, evaporite weathering, carbonate weathering and silicate weathering were 2, 37, 28, 25 and 8 %, respectively. Combined with information regarding runoff and drainage area, the annual average contribution of TDS to waters was estimated to be 1.90 ± 0.95 ton/km2 from silicate weathering, 5.68 ± 2.84 ton/km2 from carbonate weathering. Furthermore, the associated consumption of CO2 was calculated to be approximately 7.50 × 109 mol/a. The industrial and mining activities were the main sources for anthropogenic inputs, and they produced non-CO2 acids (NCA). Of all protons involved in chemical weathering, 34 % was presumed to be originated from NCA, causing 2.74 × 109 mol/a of CO2 degassing. Moreover, industrial inputs could play a major role in the modification of the chemicals in the water system, and they could even change the carbonate weathering rate in such an intensively industrializing region. In North China, the chemical weathering associated with NCA was found to be significant for the first time. © 2016, Springer-Verlag Berlin Heidelberg.
Wang D.,Shandong Jiaotong University |
Fang X.,Hubei University |
Huang J.,Shandong Provincial Institute of Land Surveying and Mapping |
Xing Z.,Land and Resources Bureau of Shandong Feexian
Applied Mechanics and Materials | Year: 2012
Qingzhou-Linshu super highway, spanning 228.333km, is located in the center of Shandong province, which forms a south-to-north expressway channel. Undoubtedly, it's an important part of Shandong highway network. Approximately, it runs from south to north and one projection zone is enough to satisfy relevant requests of horizontal coordinate system; From Qingzhou to Mazhan Town, Yishui County, most are hilly and mountainous terrain while from Mazhan Town, Yishui County to Linshu County, most are plain terrain, except for a few rolling terrain. As a result, fourth-order leveling control network is enough to meet the requirements of reconnaissance survey, design and constructive lofting. As the expressway and Ji-Qing south line carry out reconnaissance and design simultaneously and form an interchange at Mazhan Town, Yishui County, plus tight time and intense work, the systemic conformance of horizontal coordinate system and vertical datum are in high demand. The report analyses and discusses the adoption of horizontal and vertical network's starting points, layout, observation, data processing and adjustment, together with eliminating the coordinate division and elevation value's step of the same control point. In the meantime, it analyses how to make rapid aerial photogrammetry for the whole line with the scale of 1/2000, so as to improve the precision and reliability of horizontal and vertical datum as well as speed up the process of charting and utmostly satisfy the demand of highway reconnaissance and design. © (2012) Trans Tech Publications, Switzerland.
Zhu W.-S.,Shandong University |
Chen Y.-J.,Shandong University |
Li S.-C.,Shandong University |
Yin F.-Q.,Shandong Provincial Institute of Land Surveying and Mapping |
And 2 more authors.
Tunnelling and Underground Space Technology | Year: 2014
DDARF (Discontinuous Deformation Analysis for Rock Failure) is an improved method of DDA (Discontinuous Deformation Analysis method), while there are only uniform grids in the original DDARF, and multi-scale grid meshing method cannot be realized. A multi-scale grid meshing method for DDARF is proposed to rock failure analysis, which balances off between the calculation accuracy and computation time. Simulations with multi-scale grid model and uniform grid model are established respectively, and compared with the laboratory tests; this multi-scale grid meshing method is applied to progressive failure process for jointed surrounding rock, and influence on crack propagation by the different lateral pressure coefficients K0 of in situ stress is analyzed. It is concluded that this multi-scale grid meshing method for DDARF is feasible and the calculation accuracy can be improved with the same grid number. The proposed method is able to increase the computation efficiency by reducing the computation time when simulating underground cavern excavations, at the same time maintain the calculation accuracy. With increase of the lateral pressure coefficient K0 of in situ stress, the main cracks propagating zones are moved gradually from both sidewalls of the cavern to the arch crown and floor. This method improves the DDARF to large projects, and it can analyze the progressive failure process of rock more effectively. © 2014 Elsevier Ltd.
Dong L.,Wuhan University |
Shu H.,Wuhan University |
Niu X.,Shandong Provincial Institute of Land Surveying and Mapping
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University | Year: 2013
A spatial association rule mining method is proposed in this study, including support counting method based on overlay analysis and area calculation, and corresponding mining algorithms. Using this method, the extraction of spatial transactions is not needed, and association rules can be mined out directly from layers of polygon features. Besides, the results are easy to be visualized with the help of GIS. An experiment with real-world data shows that this method is valid and efficient, and the result can be further analyzed with screening and visualization methods.