Entity

Time filter

Source Type


Zhang X.,Zhejiang University | Jia Z.-H.,Jiangsu Province Electrical Power Design Institute | Wu S.-P.,Jiangsu Province Electrical Power Design Institute | Wu J.-H.,Jiangsu Electric Power Company | And 3 more authors.
Dianwang Jishu/Power System Technology | Year: 2010

To evaluate the impacts of electromagnetic environment due to the arrangement of quadruple-circuit transmission lines belonging to voltage classes of 500 kV and 220 kV on the same tower, the strength of power frequency electric field and magnetic field, the values of the radio interference (RI) and audible noise (AN) corresponding to typical tower type and transmission lines are simulated and calculated by the software CDEGS, meanwhile the influences of such factors as arrangement of conductors and their heights on electromagnetic environment beneath the transmission lines are analyzed. Calculation results show that under the minimum wire-to-ground height of conductors specified in the rule, all the strength of power frequency magnetic field, and the values of RI and AN can satisfy the requirements specified in national environmental standards, however the strength of power frequency magnetic field is the key factor to judge whether the electromagnetic environment of transmission line conforms to the specified standard. According to the specified limitation 4 kV/m for power frequency electric field the recommended width of the corridor is proposed and on this basis the optimal conductor arrangement modes corresponding to two typical tower types and transmission lines are given. Finally, several suggestions to improve the power frequency electric field beneath transmission lines are put forward. Source


Zhou Y.-Q.,Jiangsu Province Electrical Power Design Institute | Xu Q.,Jiangsu Electric Power Company | Shen J.-R.,Jiangsu Province Electrical Power Design Institute
Yantu Lixue/Rock and Soil Mechanics | Year: 2013

Void ratio is one of the most important evaluation indicator of the silt compactness; the study shows that there are certain corresponding relations between liquefaction indexes and void ratio of saturated silt subgrade treated with vibroflotation; when the post-treated void ratio drops to bellow 0.75, the liquefaction of saturated silt subgrade could be eliminated. Based on the testing result and three-phase composition analysis of soil before and after the vibroflotation, the vibration effectiveness and compaction effectiveness of vibro replacement stone column are quantified; and the estimate method of post-treated void ratio is also derived. Compared with measured values, the estimate values calculated through the estimate method have errors within ±1.5%. Meanwhile, the estimate method of post-treated void ratio are used to rapidly approach the optimal combination of pile spacing and pile diameter, so as to provide a reliable basis for saving the cost and speeding up the progress of pile testing. Source


Dai H.-J.,Nanjing Southeast University | Dai H.-J.,Jiangsu Province Electrical Power Design Institute | Liu X.-L.,Jiangsu Province Electrical Power Design Institute | Ren Z.-J.,Jiangsu Province Electrical Power Design Institute | Wei H.,Jiangsu Province Electrical Power Design Institute
Yantu Lixue/Rock and Soil Mechanics | Year: 2011

It is a new idea to adopt pile-net composite foundation for circular coal yard in fossil power plants, while not only certain soil strength is required to bear the upper load, but also the influence of soil deformation in load area on ring foundation shall be taken into account. Through prototype test and study on pile-net composite foundation of circular coal yard, this paper gives an introduction to that how to test stress and strain of pile, soil and cushion under large-area load. During the process, two loading and testing schemes were designed, while two layers of geogrids were arranged in test zone 1 and no geogrids in test zone 2. Based on the test results of two test zones, the paper investigates the depth and range of influence of large-area load on soil deformation inside and outside the load area, and analyzes the variation principle of vertical and lateral stress of cushion and soil in different elevations. Then combining with the change of pile axial force of middle pile and boarder pile in load area, the negative friction of upper soil is calculated. According to the stress of cushion and soil near the cap table, the pile-soil load sharing ratio and stress ratio are computed. Therefore the effects of geogrids on stress and strain of soil inside and outside the load area are deduced to provide objective technical parameters and suggestions on the design and construction of pile-net composite foundation of circular coal yard. Source

Discover hidden collaborations