Erection workbench and construction process

Abstract: The present invention provides a frame constructing process and an erection workbench for constructing frames for reducing the cost for assembling frames, for making it possible to execute under any weather conditions, further for shortening the term of works, and for enabling to check the safety in executions, to automate executions and to save labor. The erection workbench for constructing frames in the present invention comprises a post (B) provided at the inside of four columns composing the minimum unit of the frames, a workbench (1) erected between the intermediate portions of a post (2), a roof (4) or a workbench (8) erected between the top portions of the post (2), and a lifting crane (3) suspended from the workbench (1), the roof (4) or the post (2), and the post (2) is composed of a fixed column (2a) supported to a beam (B) at the downstairs side and a column base (2b) connected to the lower end of the fixed column (2a) and expandable and shrinkable against the fixed column (2a).

Description: This invention relates to a process for constructing frames and an erection workbench for constructing frames for setting up the frames of a steel structure, a precast concrete structure or the like by assembling preliminarily prepared members on site. A method for constructing frames by on-site assembling the columns and beam members made of structural steel and those made of precast concrete is normally proceeded, as a main point, by lifting up columns and beam members by means of a lifting crane placed on the circumferences of buildings, constructed beams or slabs and by assembling and combining these columns and beam members under the condition having no work scaffolds, as shown in Fig. 14. In this method, an arm derricking type of tower crane, an arm horizontal type of tower crane or the like, as shown in Fig. 17, is used as a lifting crane, but the numbers of cranes to be used are made as little as possible by using much larger cranes with their lifting radii. As a result, as the cranes are scaled up and become heavier, the columns and beams have to be reinforced by placing braces within the frames as illustrated in order to support the load of the cranes, and the increasing of costs becomes unavoidable. In addition, as any scaffolds cannot be provided to the columns and the beams until the assembly of the columns and the beams is completed, the assembling work for the columns and the beams has to be practiced in the condition having no scaffolds, and this enforces the workers to practice very dangerous operations that they directly climb the columns and walk on the beams, resulting in the serious shortage of the workers. Furthermore, as roofs cannot be placed at the constructing time of frames, the preceding operation has to be done on the wet steel aggregates in case of rain, and due to the remarkable increase of danger, the works in case of rain weather can help stopping in the present being from the standpoint of safety. In the consideration of these above-mentioned conventional circumstances, an object of the present invention is to provide newly a method not only for reducing frame assembling cost but also for being executable under any weather conditions, further for shortening the term of works and at the same time for improving the safety, and it is also to provide a process for constructing frames and an erection workbench for constructing frames for enabling to automate executions and to save labor. The use of cables to elevate a crane platform within a constructed frame is known from US 3,217,896. Further, elevation of platforms within a chimney or tower structure under construction by means of a slideable column fitted centrally within the platform is disclosed in FR 1,181,529. For dissolving the above-described subjects, the erection workbench for constructing frames (will be designated simply as an erection workbench thereafter) according to the present invention is composed as the following description. According to the present invention there is provided an erection workbench for constructing a frame comprising columns and beams wherein four of said columns constitute a minimum unit of the frame, said erection workbench comprising: a plurality of extension columns intended to be provided within said minimum unit of said frame, each of said extension column comprising a fixed column intended to be supported by said beams; and a column base connected to a lower end portion of said fixed column, said column base being expandable and retractable within said fixed column; a workbench supported at an intermediate position of said extension columns; a roof supported at an upper end portion of said extension columns; a lifting crane suspended from said workbench, said roof or said extension columns; wherein said erection workbench comprises a plurality of tie-beams attached to lower positions of said fixed columns; and a plurality of wheels provided at said tie-beams such that said wheels roll on said beams for changing the position of said erection workbench. A process for constructing frames according to the present invention also bases on the following process. The frames are constructed in turn in an upper direction by repeating such procedure of lifting up the upstairs column member and the beam member of the frame to be constructed by a lifting crane installed vertically to a workbench, a roof or a post to practice their assembly, and then, after assembling them, making the fixed column and the workbench lifted by making the column base expanded, making the fixed column or the wheels supported to the upstairs beams, and assembling the column member and the beam member again, under the condition for making the fixed columns or the wheels of the erection workbench supported on the already constructed downstairs beams. The frames are also constructed in turn in a lateral direction while moving the erection workbench laterally by sliding it on the already constructed beams. In the present invention, the filling and loading on the erection workbench is practiced by its own efforts while it is followed as a main point by making the posts for supporting the workbench to be a work scaffold expandable and shirkable, expanding the posts every time a single layer portion construction is ended, raising the fixed column and the workbench upstairs, fixing the fixed column on the upstairs beams, providing the slidable wheels on the beams that have been already constructed, and by moving the wheels horizontally while making the wheels slided on the already constructed beams every time the construction of one division of the same stage is ended. At the same time, no large-scale tower crane can be needed by attaching the lifting cranes for lifting up the column member and the beam member and suspending into a predetermined position to the workbench, the roof or the post. In addition, in accordance with this, the reinforcement by the columns and the beams becomes unnecessary for enabling to reduce the execution costs. The safety in execution can be also improved by practicing the assembly of the columns and the beams while the workbench is made as a work scaffold for assembly. A series of executions such as the welding and the bolting works at the time of column and beam assembly can be also made as an automatic execution by loading various constructing robots such as an assembling robot and a welding robot on the workbench. Furthermore, any weather influences can be overcome and the efficiency in executions can be improved by erecting a roof at the upper side of workbenches. The present invention is a method for constructing the frames composed of a column C and a beam B in steel structure or precast concrete structure by using an erection workbench A for constructing frames (will be designated as an erection workbench A thereafter) and composed of a workbench 1 for assembly work as illustrated in Figs. 1 through 3, a post for supporting the workbench, a lifting crane 3 attached to them, and a roof 4 covering over the workbench 1. The post 2 of the erection workbench A basically locates at the inside of four columns C composing the minimum unit of the frame as shown in Fig. 2, the workbench 1 has the corresponding flat area to the bed area of this minimum unit, and the lifting crane 3 is suspended from the workbench 1 as shown in Fig. 3 and placed. The lifting crane 3 suspending from the workbench 1 is made freely movable within a plane in a monorail pattern for smoothing the work. The post 2 is composed of a fixed column 2a mounted on the already erected beam B at the downstairs side as shown in Fig. 3 and fixed to the beam B and a column base 2b expandable and shrinkable in an axial direction to the fixed column 2a and connected to the under portion of the fixed column. Bearing bases 2c, 2c for making the load of the erection workbench A supported by the beams B, B are projected on the lower end of the fixed column 2a while overhanging in the two directions or one direction of the side portion of the beam B. The bearing bases 2c, 2c are provided in the fixed column 2a enterably from the fixed column 2a, fallably by means of hinges or attachably or detachably in order to avoid the collision against the upstairs beams B, B at the time of the workbench 1. The intervals of a-a and b-b in Fig. 2 show the planes of a-a and b-b in Fig. 1, respectively. The fixed column 2a has the length passing through the workbench 1 from the beam B on the underside of the workbench 1 and leading to the roof 4. The column base 2b is shrunken by storing it within the fixed column 2a as shown in Fig. 3. A bearing base 2d for the burden of the load at the expanded time at the lower end portion of this column base 2b, that is, at the elevation time of the fixed column 2a is projected enterably, fallably or attachably or detachably in the similar way to that of the fixed column 2a. Figs. 4 through 7 shown the supporting condition to the beams B, B at the storing time of the column base 2b. Figs. 4 and 5 are fragmentary views taken in the X and Y directions of the arrows of Fig. 7, respectively. At the storing time of the column base 2b, the load of the erection workbench A is supported by both the bearing base 2c for the fixed column 2a and the bearing base 2d for the column base 2b stored in such a condition that the end portion lower than the bearing base is exposed, for example, as shown in the drawing. Fig. 6 shows the modification of Figs. 4 and 5, and it is a case that the column base 2b is completely stored within the fixed column 2a, the bearing base 2d for the column base 2b is projected from the cut-out formed at the lower end of the fixed column 2a, and the load of the erection workbench A is supported by the projected fixed column and the bearing base 2c for the fixed column 2a. At the erection time of the column member and the beam member, the column base 2b is stored in the fixed column 2a, and after the erection of a single layer frame is completed, the column base expands to make the fixed column 2a and the workbench 1 lifted and is shrunken to be stored after the fixed column 2a is fixed. The roof 4 is supported by the fixed column 2a which continues from the four corners of the workbench 1 to the fixed column 2a of the post 2. The roof 4 has a flat area larger than that of the workbench 1, and its circumference overhanges from the workbench 1 as illustrated. The environment on the workbench 1 is enhanced and the efficiency in works can be improved by using the raw material penetrated by light as a roofing material for this roof 4. The lifting crane 3 is added to the workbench 1 and if necessary it is suspended from the roof 4. The lift 5 for lifting mainly the column member or the beam member is provided at the external side of this post 2. This lifting crane 3 is used not only for the setting of the column member and the beam member but also for that of the curtain wall for exterior. In the embodiment, as shown in Fig. 3, a movable scaffold 1a overhanging horizontally from the workbench 1 and positioning at the lower portion of the lift 5 is provided freely enterably to improve the efficiency in works. As the dimension of the erection workbench 1 becomes variable due to the built-in type of this movable scaffold 1a, that is, the erection workbench A can be also applied to the frames with the difference in the flat area of a single unit, the conversion ratios are high, and the cost can be reduced. Furthermore, in case the flat area as a single unit is relatively smaller than that of the workbench 1, the erection workbench A is provided at the inside of the four columns C corresponding to its scale. The erection workbench A is provided every each unit of a single layer as shown in Figs. 1 and 2, and is independently lifted to the upper layer, respectively. Referring now to Figs. 1 and 2, the procedure for executing a single layer portion is described. First of all, after lifting the workbench 1 up to the position of the beam B on the upstairs side of the layer where the workbench is completed, the erection workbench A is supported by the beams B, B to store the column base 2b by fixing the fixed column 2a to the beam B, B on the downstairs side by the bearing bases 2c, 2c, by the process as shown on the left side in Fig. 1. In this condition, the column member and the beam member are erected and connected by lifting up these members by use of the lifting crane 3 and the lift 5 which are suspended from the workbench 1 and the roof 4. During this time, the downstairs floor slabs are executed by the lifting crane 3 at the lower portion of the workbench 1. Then, in the condition that the load of the erection workbench A is put a burden on the downstairs beam B by the bearing base 2d at the lower end of the column 2b, the only one layer portion of both the workbench 1 and the fixed column 2a is lifted by making the column base 2b extended, and the bearing base 2c is overhanged from the fixed column 2a, fixed to the upstairs beam B and supported by this, by the process as shown at the center in Fig. 1. Then, the column base 2b is shrunken to be stored in the fixed column 2a, by the process as shown on the right side in the figure. Subsequently, the process as shown on the left side in Fig. 1 is repeated to proceed it to the upper layer in turn. Figs. 8 through 13 show other embodiments of the erection workbench for constructing frames. In the preceding embodiment, tie-beams 6, 6 are erected at the lower end between the column bases 2b, 2b for the post 2, respectively, and a plurality of wheels 7, 7 capable of sliding on the erected beams B, B by power are installed to the tie-beams 6, 6 erected facing each other horizontally and at a certain interval in a longitudinal direction, among the tie-beams 6, 6. In such a case, as the width of the column is normally larger than that of the beam, the wheels 7, 7 are arranged enterably by the tie-beam 6 (refer to Figs. 11 and 12), fallably by the hinges (refer to Fig. 13) or attachably or detachably (not shown), not so as to collide with the already erected column C or beam B, when the erection workbench A moves horizontally and upwards. According to such a configuration, the erection workbench A can freely move the itself in either front and rear or left and right on the already erected beams B, B . Furthermore, in case the tie-beam 6 is erected at the four corners of the column bases 2b, 2b and the wheels 7, 7 are provided, respectively, the erection workbench A can freely move the itself in either front, rear, left or right direction. In such a configuration, the description of the process for constructing frames is given as follows: First of all, after the workbench 1 is moved upwards upto the position of the beam B on the side of the already erected upstairs, the erection workbench A is supported to the beams B, B by fixing the fixed columns 2a, 2a to the beams B, B on the side of the downstairs by the bearing bases 2c, 2c by the process as shown on the left side in Fig. 8, and at the same time, the wheel 7 is locked not so as to rotate. The column bases 2b, 2b are also stored in the fixed columns 2a, 2a. In this condition, the column member and the beam member are lifted up by the lifting crane 3 and the lift 5 suspended from the workbench 1 and the roof 4 to practice their erection and connection. During this time, the execution of the floor slabs on downstairs is practiced by the lifting crane 3 at the lower portion of the workbench 1. After all the processes within the reachable range of the workbench 1 is complated, then, the fastening for the bearing bases 2c, 2c and the lock for the wheels 7, 7 are temporarily cancelled and the erection workbench A is supported by the wheels 7, 7 so as to make the erection workbench A movable. Furthermore, as the total weight of the erection workbench A loads on the wheels 7,7 in such a condition, at least four wheels 7,7 are provided on one side for enabling to support firmly. Then, the erection workbench A is slid on the beams B, B and moved laterally to the next work plot, and then the erection workbench A is supported to the beams B, B by fixing the fixed column 2a to the beams B, B again by the bearing bases 2c, 2c. In addition, for practicing the works with safety, it is desirable that the works are practiced in the condition that the erection workbench A is completely fixed to the beams B, B by the bearing bases 2c, 2c. In case of a simple work, however, it can be done by making the erection workbench A supported by the wheels 7, 7 as it is without fixing it. When the construction of the same floor, that is, that of the floor installed with the erection workbench A is completed, the wheels 7, 7 are locked not so as to rotate. By the process as shown at the center in Fig. 8, both the workbench 1 and the fixed column 2a are moved upwards for one layer portion by extending the column bases 2b, 2b, and the erection workbench A is supported to the upstairs beams B, B by overhanging the bearing bases 2c, 2c from the fixed columns 2a, 2a onto the upstairs beams B, B and by fixing the overhung bearing bases to the upstairs beam B. Subsequently, by the process as shown on the right side in Fig. 1, the column base 2b is stored in the fixed column 2a. In addition, the wheels 7, 7 are overhung on the upstairs beams B, B. In the similar manner, the frames are assembled while moving the erection workbench A in a lateral direction and in an upper direction as follows: Figs. 14, 15 and 16 show other embodiments of the erection workbench A according to the present invention, and instead of installing the roof 4 between the top portions of the posts 2, 2, a workbench 8 used both as the roof is provided, on which various constructing machines corresponding to the object to be used as a lifting crane 9 or the like are provided. Other configurations are approximately same as the preceding embodiments. If this section workbench A is used, various kinds of works can be proceeded at the workbench 8 and at the upper and lower two places of the workbench 1 at this lower side, and therefore, the efficiency in works is broadly improved. Furthermore, as the lifting cranes provided under a ceiling and the post 2 become unnecessary, the safety over the heads can be attained as well. The present invention is as the above description. As the erection workbench is provided every the minimum unit of the frame, the weight of each workbench is lightweight and no large force is needed for lifting itself. As the weight lifting of the column member and the beam member can be practiced while approaching to the erection workbench, the lifting crane attached to the erection workbench with a comparatively lower capacity is good enough. Therefore, as no large tower crane of a conventional type is needed and it can do without any reinforcement of the frames, the cost reduction can be attained. In addition, the erection work of the column member and the beam member is all done on the workbench of the erection workbench, and therefore, the safety is high. In addition, the automation of the execution is possible by loading he constructing robots in accordance with the objects such as a bolting or welding robot on the erection workbench. As a result, it becomes possible to attain saving labor. Moreover, as the works can be practiced without receiving any influences of weather thanks to the existance of the roof or the erection workbench, the term of works can be shortened, the day off of workers due to rainy weather is not needed, and the efficiency in executions is brought to realization. Furthermore, as the erection workbench can raise back and forth, and move to left or right and laterally, the executable range is extremely broad per one erection workbench. Therefore, according to the sizes of buildings, the construction works can be proceeded with an extremely good efficiency by employing the possibly smaller number of the erection workbenches, resulting in cost reduction. Fig. 1 is a side view showing the main point of the execution of an embodiment according to the present invention; Fig. 2 is a plan view showing showing the above embodiment; Fig. 3 is a side view showing an erection workbench; Figs. 4 and 5 are side views showing the details of the bearing base portion at the storing time of a column base, respectively, and also are fragmentary views taken in the direction of the arrows in the respective X and Y directions; Fig. 6 is a fragmentary view taken in the direction of the arrows in Y direction of Fig. 7 and showing the modification of Figs. 4 and 5; Fig. 7 is a partial plan view of Fig. 2; Fig. 8 is a side view showing the main point of the execution of another embodiment according to the present invention; Fig. 9 is a plan view showing the embodiment of Fig. 8; Fig. 10 is an elevation showing an erection workbench; Figs. 11 through 13 show a wheel-fixing portion, respectively, in which Figs. 11 and 13 are plan views and Fig. 12 is a longitudinal sectional view, respectively; Figs. 14, 15 and 16 show further embodiments of the erection workbench according to the present invention, respectively, in which Fig. 14 is a schematic plan view, Fig. 15 is a sectional view taken along the line a-a of Fig. 14, and Fig. 16 is a sectional view taken along the line b-b of Fig. 14, respectively; and Fig. 17 is a side view showing a prior art process for constructing frames. 1 ... workbench; 1a ... movable scaffold; 1b ... movable scaffold; 2 ... post; 2a ... fixed column; 2b ... column base; 2c ... bearing base; 3 ... lifting crane; 4 ... roof; 5 ... lift; 6 ... tie-beam; 7 ... wheel; 8 ... workbench; 9 ... lifting crane; A .. erection workbench for constructing frames (erection workbench); B ... beam; C... column

Claims: An erection workbench (A) for constructing a frame comprising columns and beams (B) wherein four of said columns (C) constitute a minimum unit of the frame, said erection workbench (A) comprising: a plurality of extension columns (2, 2a, 2b) intended to be provided within said minimum unit of said frame, each of said extension column (2, 2a, 2b) comprising a fixed column (2, 2a) intended to be supported by said beams (B) and a column base (2b) connected to a lower end portion of said fixed column (2, 2a), said column base (2b) being expandable and retractable within said fixed column (2, 2a); a workbench (1) supported at an intermediate position of said extension columns (2, 2a, 2b); a roof (4) supported at an upper end portion of said extension columns; a lifting crane (3, 5) suspended from said workbench (1), said roof (4) or said extension columns; characterised in that said erection workbench (A) comprises a plurality of tie-beams (6) attached to lower positions of said fixed columns (2, 2a); and a plurality of wheels (7) provided at said tie-beams (6) such that said wheels roll on said beams (B) for changing the position of said erection workbench (A). An erection workbench (A) according to claim 1, wherein said plurality of wheels (7) are retractably attached to said tie-beams (6) so as to bypass said column members (C) when changing the position of said erection workbench (A). An erection workbench (A) according to claim 1, wherein said plurality of wheels (7) are hingeably attached to said tie-beams (6) so as to bypass said column members (C) when changing the position of said erection workbench (A). A method for constructing the frames composed of columns (C) and beams (B) by the erection workbench (A) according to claim 1, comprising the steps of: repeating a procedure for suspending an upstairs column member and beam member, assembling said members, after their assembly, lifting up the fixed column and the workbench by extending the column base, making the fixed column or wheels supported to the upstairs beam, and assembling the column member and the beam member, in the condition that the fixed column or the wheels are supported to the already constructed downstairs beam by making the workbench slide on the already constructed beams and moved horizontally.

Inventors: SAITO MAKOTO C O KAJIMA CORPOR, SAITO, MAKOTO, C/O KAJIMA CORPORATION
Applicants: KAJIMA CORP, KAJIMA CORPORATION
Application year: 1991
Main classification: E04G21
IPC codes: E04G21, E04G3