Abstract: This paper points out the necessity of using the construction technology of one-time completion of pillar installation in the upper construction of high-speed railway catenary by comparing the traditional construction technology of the upper part of the contact line and the construction technology of one-time completion of the pillar installation. The construction technology of the upper part of the high-speed railway catenary is expounded in detail from the aspects of on-site surveying and mapping, construction data calculation, pre-installation of accessories, installation of construction vehicles, and over-pulling technology of bearing cables and catenary wires. .Key words: catenary; construction technology; super pull
1-Complete the construction process of pillar installation at one time
The installation of the pillars is completed at one time, and the procedures include installation construction drawings and process requirements, surveying and mapping of the technical status after the pillars are buried on site (collecting on-site intelligence data), computer data processing, generation of installation construction tables, centralized installation construction and construction vehicle installation .
2 Construction technology of the upper part of the high-speed railway contact line
① On-site surveying and mapping. To survey and map the installation status of all pillars, not only the status of each pillar line needs to be displayed with data, but also the accuracy of the surveyed data should be in accordance with high standards.
②Construction data calculation. The dimensions of pillar installation and prefabrication are calculated by measuring the pillar buried depth, pillar inclination rate, side limit, and line over-height obtained by surveying and mapping, and then calculating the length of the tie rod, the saddle, and the specific installation position of the required positioning device. The measurement program can be programmed with a computer, and the data of on-site surveying and mapping can be directly input to obtain the required pre-configured installation size.
③Accessories are pre-installed. According to the measurement results, the wrist and arm are pre-installed in a centralized manner. _
④ Installation of construction vehicles. In order to facilitate the operation, the positioning pipe and the positioner are pre-configured separately during installation. For the sake of accuracy, after the installation of the bearing cable is completed, the orientation of the positioning ring shall be surveyed, reviewed and checked. The strings are installed one at a time, and the rest are installed before the wires are erected.
3. Over-pulling technology of load-bearing cable and catenary wire
①The method of eliminating the initial elongation of copper trolley wires and steel strands in my country. The influence of the initial elongation of copper trolley wires and steel strands is basically reflected in two aspects: first, the extension of the lower end of the anchoring leads to a large deviation in the height of the supplementary weight, which will cause the bad problem of the weight stuck; second, The extension of the determined position by the hanging causes the vertical deviation of the positioning object and the hanging object to be too large, and then there is a large lateral deviation, which damages the stable "pantograph" operation relationship.
②Complete the stance of copper trolley wire and steel strand at one time to eliminate the method of initial elongation and over-stretching and the establishment of over-stretching tension. The establishment of the super-tension method is stipulated in the relevant manuals for the construction of high-voltage suspended transmission lines. In order to clarify the corresponding relationship between the initial elongation of the conventional GJ70 wire and the TCG110 wire, the overdrawing time and the overdrawing tension, according to the suspended power line to exclude the initial elongation and the Japanese standard for overdrawing, use 30
About the author: Xu Meng, China Railway Seventh Bureau Group Electric Engineering Co., Ltd.
For a test wire with a length of m, use a supplementary device for the over-tension device to do a wire over-tension test study, and then obtain the corresponding relationship between the initial elongation of the wire and the over-tension time and over-tension tension.
③ super pull technology. Do not occupy the closed point super-pulling technology: stance lifting, anchoring and falling mass attachments - bearing cable or catenary wire installation - central anchoring installation - lower anchoring and falling mass attachment installation - overdrawing 30 ~ 60 min - anchoring, select The supplementary device performs overstretching as an auxiliary tension. Occupying the closed-point super-pulling technology, the procedure of the gantry line car process: lifting the rope with the limited height of the anchor stance - installing the bearing cable or catenary wire - fixing the super-pulling - super-pulling the anchor for 10~30 minutes.
4 Effective control of errors during construction
①The control of measurement error. Before carrying out the overall chord construction work, we need to measure the span of the pillars first, and at the same time arrange the chord spacing along the rail, and then mark it on the rail with bright red paint. The measurement error needs to be reduced in the positive within the range of minus 5n™.
②Tension control of load-bearing cable and contact line The tension of load-bearing cable and contact wire is accomplished by a pulley compensation constant tension device that depends on the weight of the weight attached to it. It can be seen in the whole calculation that the tension of the wire can have a direct effect on whether the hanging string is long or short. Therefore, it is necessary to select those combined components with higher transmission efficiency. At the same time, it is also necessary to grasp the error of the weight of the falling mass, and the error needs to be controlled within the range of plus or minus 1%.
③ The error of the whole hanging string during the production and actual installation needs to be effectively controlled. Effective calculation is carried out according to the relevant calculation program of the overall hanging string, the data is collected and measured, and the data is designed, and finally the construction data is sent to the construction team. Before production, the bronze stranded wire needs to be pre-stretched with a tension of 115 ~ 210 kN, and the pre-stretched wire is unloaded without winding. When pressing, the hanging string must be passed to the bottom of the crimping hole. After pressing one end, compare it with the length standard specified on the work ticket, and then start pressing the other end of the pre-pulled wire. The error needs to be controlled within the positive within the range of minus 2 mm.
In short, the application of a comprehensive construction technology in the construction of the upper structure of the catenary can effectively improve the efficiency, reduce the rework rate and various unnecessary labors, improve the relationship between the pantograph and the catenary, and improve the quality of the electric locomotive. The construction and installation technology that the upper part of the catenary is in place at one time will surely play its due role in the future catenary project.
