Ryu, Ji Seung (103-802, Hanil apts. 516, Yulcheon-dong, Jangan-g, Suwon-si Kyungki-do 440-829, KR)
| 1. | A method for constructing a transmission tower, comprising the steps of, disassembling a equipment as segments at a flat ground; processing said segments of base footing or steel concrete network; transferring the assembled segments to the spot by a helicopter; installing said segment pulled up with said helicopter in the air maintaining the static state; connecting at least three braces between main pillars permitting the eccentric center not to deviate the acceptable tolerance with a unit truss pulled up at high altitude wherein if the height of the steel tower to be assembled is above 30 m said unit truss is to be assembled below 10 ton for being pulled up by helicopter based on the length of said main pillar at the flat ground; and assembling said unit truss pulled up with said helicopter in the air maintaining the static state. |
| 2. | The method according to claim 1, wherein if said slant brace installed between said main pillars deviates from said unit truss, a supplementary connecting part is installed at the top and bottom of said main pillar and only braces in parallel with said supplementary connecting part without connection of said slant brace. |
| 3. | The method according to claim 1, wherein a guide device is installed at the upper part of said unit truss. |
A METHOD FOR CONSTRUCTING A TRANSMISSION TOWER BY HELICOPTER
Technical Field
[1] The present invention relates to a method for constructing a transmission tower by helicopter in the area of islands and precipitous mountains and the purpose of the present invention is to reduce painstaking of construction on the spot by disassembling a excavation equipment in the size of 10 ton at a flat base, and at the same time is to achieve segments for assembling by taking advantage of pulling-up with a helicopter and maintenance of suspension state of the helicopter for direct-use on the spot to consequently shorten construction period and simultaneously to secure bolts of tower segments with ease. Background Art
[2] More specifically, the purpose of the present invention is to make a footing of deep foundation or a steel concrete frame to be segments for assembling within the maximum weight pulled up by a helicopter in order to apply on the spot as it is and at same time is to make a excavation equipment to be segments for assembling within the maximum weight, and also the purpose of the present invention is to convey the segments to a place for constructing by the helicopter and to construct the segments at exact place on the spot with the helicopter kept in the air to reduce the necessary time for constructing work, to work easily and to decrease the risk from working at a high altitude by reducing the number of work, to obtain the stability of the structural mechanism to stand against a strong wind with the velocity of 40 to 50 m/s by reducing the number of connections at the main pillars and to construct a transmission tower not to damage natural circumstance. Disclosure of Invention Technical Problem
[3] The construction of power transmission with super-high voltage is inevitable owing to the increase of electric energy consumption as the construction of high way is inevitable for large scale of transportation. In the meanwhile, a transmission tower with the height of 30 to 100 m is generally constructed in a mountainous area. And a steeped mountain ridge or a deep valley may be between a transmission tower and other transmission tower owing a rugged mountain.
[4] Referring to the method for constructing a tower of the power transmission under the above condition of natural geographic, primarily the method for constructing the entering road that may be used for transferring the tower materials and tower-base con-
struction materials may be considered. However, the above method of entering road construction requires about 8 % of the terminal incline steep, and in particular the terminal incline steep may be permitted up to 18%, but it is impossible to extend over the above range.
[5] If the value of terminal incline steep is above 18%, it is impossible to construct a transmission tower. It is the worst disadvantage that it takes too long time to construct an entering road before the main work that construction of a transmission tower. As further disadvantage of the above method, the natural circumstance should be destroyed by means of forest damage owing to the construction of the entering road.
[6] The limit of terminal incline steep may be overcome by the method of cable carriage 1 (see Fig. 1). The method of cable carriage 1 may permit up to 45 degrees of terminal incline steep. The method of cable carriage 1 has wider range of terminal incline steep than the method of entering road construction because the former can permit the width of terminal incline steep to be adjusted by a cable 11 and the a pillar supporting the cable 11. The cable 11 should be in a straight line. According to the method of cable carriage 1 the maximum weight transferred by the carriage 12 is about 2 ton. With such capability of transportation a footing of deep foundation, reinforced concrete frame, ready mixed concrete or tower truss may be conveyed as a member unit, but the segments for assembling that can be utilized at each of four spots separated from each another in a long distance may not be unloaded directly at the deep well.
[7] Furthermore, in the case of the equipment (excavation etc), after each component disassembled as the smaller weight less than 2 ton is conveyed on the spot, some additional equipment with necessary function (for example, the function of a crane) will be required because the above components has to be lifted or transferred according to the height or length for assembling.
[8] There is the monorail method, but it is very similar to the method of cable carriage
1. That is, the terminal incline steep may be permitted up to 45 degree, the road has to be in a straight line and the maximum weight to be conveyed by the monorail method is about 2 ton. The monorail method has the same disadvantage as the method of cable carriage 1. Technical Solution
[9] There is the helicopter method. The helicopter method is known as the unique method solving the problems occurring from constructing the entering road, installing cable carriage or monorail at a stroke. But with the present kinds of helicopter the use of helicopter is constrained to the transportation of materials for construction of iron tower based on the weight of 2 ton, and there is still a serious problem that the footing
of deep foundation or steel reinforced concrete assembled at the flat base and assembling segments for steel tower truss cannot be conveyed on the spot. [10] The small helicopter (such as 2 tons grade) has not compartment for loading and cannot transport assembling segments in 2 tons weight. With freight crane the device for avoiding air rotation can be attached. If a helicopter has not the device for avoiding air rotation, it is impossible to assemble the steel tower. The small helicopter (such as 2 ton-grades) can only transfer the materials for construction. For transferring the assembling segments at least 6 ton-grade-helicopter is necessary. Advantageous Effects
[11] In view of construction work, the work can be divided into transmission tower construction made in 30 to 100 m height and base construction to support the transmission tower construction, and the necessary condition for the base construction is 20 m * 20 m in area and above 20 m in depth. For constructing such base ground 5 and steel tower above 10 ton of assembling segment is suitable for the construction. Furthermore, for such construction work excavation equipment for excavating the ground and telescopic 4 and the like are required, and the transferring weight of units for disassembling for re-assembling should be at least 10 tons.
[12] In case of transmission construction, the assembling work should be performed at least in 30 m height, and therefore the numbers for assembling should be in the minimum, if possible, for the efficiency of the work and the decrease of the risk. Considering the above-mentioned conditions, the method of assembling segment may be most suitable. Fortunately, it has to be noted that a helicopter having above 10-ton capacity was developed. The capacity of helicopter is not sufficient for construction of the transmission steel tower. For example, the steel tower with the height of 30 to 100 m should stand against the strong wind with velocity of 40 to 100. The crosswise force due to the strong wind transmits to the main pillar of the steel tower, and therefore the number of connections of the main pillar should be reduced for obtaining the structural stability against to the crosswise pressure. In other words, in case of the assembling segment the maximum length of the pillar has to be at least 10 m in length and at the same time the maximum weight of the pillar has to be at least 10 ton in weight.
[13] Though there is a case that the length of the main pillar is 10 m in a conventional method, each member has to be pulled up by tower crane and to be assembled directly by the work. But the method according to the present invention differs from the conventional method in that assembling segments that has a main pillar with at least 10 ton of maximum weight and at least L = 10 m of maximum length is transferred by a helicopter and is assembled to install by a tower crane, and therefore the present invention is based on a different construction concept from the conventional method
that a tower crane for pulling up has to be equipped separately and each member of construction has to be assembled directly by the worker.
[14] Furthermore the risk from construction is higher as well as the period for construction is longer because each steel concrete of deep foundation has to be assembled for structuring a frame and each member of construction has to be assembled at a high altitude in the spot of base work and tower work in a worse construction circumstance such as mountainous area.
[15] It is general case to construct a flat base for transmission tower construction. The flat base is preparing work site for unloading materials required in the mountainous spot work and for processing the materials for suitable scale according to the predetermined design.
[16] The flat base is usually located apart 2 to 3 km form the spot of transmission tower construction work. The more the number of disassembling works is in the flat base, the more, the more the number of assembling works is in the spot, and to the contrary the less the number of disassembling works is in the flat base, the less the number of assembling works is in the spot. In the other word, if the works in the flat base is constrained to cutting the member based on the standard of design or processing, workers in the spot has to assemble all the member, and therefore the work in the spot increases to the same amount.
[17] On the contrary if assembling segments is made under the condition of W=IO ton and L = 10 m in the flat base, the amount of work in the spot decreases up to the same amount. However, because up to now, as mentioned above, the transferring means capable of conveying above materials of 2 ton cannot be used, it is cannot conceived that an assembling segment manufactured as above 2 tons may be conveyed in the spot.
[18] As mentioned above, the method of conventional steel tower construction has been performed by means of assembling member, and the method of the steel tower crane construction corresponds to the representative method. As other conventional construction method there are Dereth method and movement crane construction method, but the methods is similar to the tower crane construction method in that each member should be assembled in order.
[19] Otherwise the helicopter method has advantages that the conveying function and pulling up function in the steel tower construction method are simultaneously performed because a helicopter moves freely over rugged mountains and can maintain a static state at any position on the air as shown in Figure 3. The present invention utilizes two functions of helicopter and the number of connections decreases for standing the strong wind by manufacturing assembling segments under the condition of W = 10 ton and L = 10 m, and according to the present invention at least there brace
may be installed between main pillars to keep a combining hole of bolt from deviating a permitted tolerance by eccentric center in the course of transferring the assembling segments through the air.
[20] The tower material of the present invent comprises steel pipe and angle.
[21]
Brief Description of the Drawings
[22] Fig.l depicts schematically the transportation of the materials according to the conventional cable and carriage. [23] Fig.2 depicts the carriage used the cable.
[24] Fig.3 depicts the flight route of a helicopter.
[25] Fig.4 depicts the representative view according to the present invention.
[26] Fig.5 depicts the front view indicating the height of the tower according to the present invention. [27] Fig.6 depicts the view for describing the excavation of the deep foundation by telescopic. [28] Fig.7 depicts the representative view of the base work process according to the present invention. [29] Fig.8 depicts the view for describing the construction of the base steel concrete segments by the helicopter. [30] Fig.9 depicts the view for describing the construction of the deep foundation segments by the helicopter. [31] Fig.10 depicts the cross-sectional view of the deep foundation steel concrete according to the present invention. [32] Fig.l 1 depicts the representative view of the finished deep foundation according to the present invention. [33] Fig.12 depicts the representative view showing the helicopter to convey the assembling unit truss according to the present invention. [34] Fig.13 depicts the front view of Fig.11a.
[35] Fig.14 depicts the representative view of the assembling unit truss according to other example of the present invention. [36] Fig.15 depicts the front view of Fig.12a.
[37] Fig.16 depicts a preferable embodiment showing the helicopter to convey the equipment. [38] Fig.17 depicts a illustrative view of the guide system.
Best Mode for Carrying Out the Invention
[39] In the follow the contents of the present invention will be give in detail.
[40] The present invention comprises the steps;
[41] assembling a footing of deep foundation 7 and a segment of steel concrete network
71 in the flat base; transferring said segment of assembled steel concrete network 71 in the spot by helicopter; constructing a pulled up segment 71 by helicopter that maintains in the air and in the static state; standardizing the maximum length of main pillar 3 as L = 10 m in case of constructing above 10 m steel tower and at the same time assembling as unit truss 8 such that the maximum weight to be conveyed by helicopter is 10 ton while connecting at least three braces 81 between main pillars not to deviate a permitted tolerance of eccentric center with the unit truss 8 pulled up; and assembling unit truss 8 pulled up with the helicopter maintained at a some height in the static state. The pillar or brace may be a steel pipe or an angle.
[42] In the meanwhile, as shown in figure 12 and 13, if a slant line brace 81 deviates from the main pillar 3, a supplementary connecting part 82 may be installed at the top and bottom end of the main pillar 3 and only the brace in parallel to the supplement connecting part 82 may be installed without connecting the slant lint brace 81.
[43]
[44] The detailed description of the present invention will be given using the accompanied drawings in the following.
[45] The base construction and the steel tower construction will be described individually using such as the transfer function of helicopter and tower crane. For the base construction, excavation equipment is necessary. If the excavation equipment is apart according to the function on the base of 10 ton at the flat base, the amount of work for assembling in the spot may be reduced without the capability reduction of the excavation equipment (see figure 16). The work efficiency in the spot depends on segmenting according to the function. For deep foundation 7 a base footing steel concrete network and the steel concrete frame of a sphere shape part are necessary. If the above materials are transferred in the spot to be installed after being assembled in the flat base on the base of 10 ton and then the materials are placed at the proper position with the materials pulled up by the helicopter, then the amount of work in the spot may be reduced. A steel tower construction means the construction of above 30 to 100 m steel tower and can be accomplished by assembling the materials for construction. If each material has to be assembled individually and in order, the time for working will be loner and the danger from working will be higher. However, as shown in figure 7, if assembling segments are conveyed to the spot after manufactured in the flat base and the assembling segments are pulled up by helicopter at the place to be assembled, the construction period will be reduced greatly and the assembling work at the high altitude will be performed with ease.
[46] The maximum weight of the assembling segment is W = 10 ton, the maximum length of main pillar is L = 10 and at least three braces 81 has to be installed between
the main pillars.
[47] The maximum weight W= 10 ton results from the fact that the maximum weight pulled up by helicopter is 10 ton, the maximum length L = IO m results from the fact that the connection number of weak part should be reduced for standing against the strong external pressure such as a strong wind in the velocity of 40 to 50 m/s, and at least three braces 81 between main pillars results from the fact that the stability of structural mechanism should be assured from the eccentricity of the center of gravity caused in course of high altitude transfer of assembling segments. Even though a device for avoiding the air rotation may be equipped, the eccentricity of the center of gravity in the course of high transfer is inevitable. If the deviation error to the coupling hole is over the permitted tolerance owing to the eccentricity, the connection work in the high altitude will be more difficult and then the facility of helicopter will be inefficient owing to the delay of work time.
[48] If the slant brace 81 installed between the main pillars 3 deviates from the main pillar, as shown in figure 8, the slant brace 81 will be omitted and a supplementary connecting part 82 may be installed at the top or bottom as supporting point for being pulled up by the helicopter and hence the stability of structural mechanism may be obtained.
[49] The construction method according to the present invention may be applicable to the construction of transmission tower in the mountainous area, on the sea and traverse the sea, the construction of transmitting-receiving tower for broadcasting and communicating, the construction of steel tower for high speed rail and the construction of steel tower for ski as well as the construction of transmission tower.
[50] In the meanwhile, a guide device or guide system 9 may be utilized in the course of assembling the unit truss regardless of the steel pipe tower or angle tower (see figure 17). The guide device is suitable for fitting flange holes (in case of angle tower, the angle hoes) with the greatest ease and safe when the lower part and upper part of the tower is assembled. The bolt connection work may be performed easily at the high altitude when the device is utilized.
[51] A helicopter particular that may be used in the present invention is shown in table 1. [52] [53] Table 1 A helicopter particular relevant to the present invention
[54]
Mode for the Invention
[55] The present invention has advantages in the following. [56] For example, If the necessary time for transferring a excavation equipment at the spot is considered, when the equipment is transferred by a small helicopter the equipment is disassembled at the flat ground to transfer at the spot and then the equipment has to be assembled. In such case a separated crane is necessary. Supposed from the experience the necessary time is generally 15 day for disassembling and assembling. However, according to the present invention, if the excavation equipment is disassembled below 10 ton, eight hours is sufficient for disassembling and assembling. In assembling the function of crane is assigned to the helicopter, and therefore a separated crane is unnecessary. The method of the present invention has advantage to reduce greatly the working time.
[57] In the meanwhile, using the characteristics of helicopter such as the transferring function to move with no obstacle and the tower crane function to maintain the static state the segments assembled well at the flat base can be conveyed at a base construction spot where the footing of deep foundation and the steel concrete frame are constructed and at the steel tower construction spot and then the construction is performed with the use of tower crane function of helicopter, and hence the necessary time for construction can be reduced greatly and the damage of the natural circumstance will be made as small as possible.
[58] Furthermore, because the segment is W = 10 ton and L = IO, and at least there braces are contained to make the number of connection parts minimized. Therefore, the
location of connection holes remains within the tolerance in spite of the eccentricity of the center of gravity. As result, the stability of structural mechanism to stand against a strong wind above the velocity of 40 to 50 m/s can be obtained as well as the work for assembling the segments can be performed with ease.
[59]
Industrial Applicability
[60] The present invention relates to a method for constructing a transmission tower by helicopter in the area of islands and precipitous mountains and the purpose of the present invention is to reduce painstaking of construction on the spot by disassembling a excavation equipment in the size of 10 ton at a flat base, and at the same time is to achieve segments for assembling by taking advantage of pulling-up with a helicopter and maintenance of suspension state of the helicopter for direct-use on the spot to consequently shorten construction period and simultaneously to secure bolts of tower segments with ease.