JP3406370B2 - Horizontal shaft construction method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a horizontal shaft, and more particularly to a method suitable for constructing a horizontal shaft having a large cross section. 2. Description of the Related Art As an example of a case where a large-diameter plumbing or subway construction is carried out in the ground, conventionally, an excavated cross section is divided into a number of sections, and a support is provided for each section. A method of excavating toward the tip while installing is known. FIGS. 6 and 7 are for explaining the conventional method of constructing a horizontal shaft, and in these figures, reference numeral 1 denotes a shaft. The shaft 1 is a working shaft used when the horizontal shaft 2 is constructed, and is constructed before the horizontal shaft 2 is constructed, and the parent pile 3, the sheet pile,
The stomach is stopped by the belly 4 and the tension 5. [0003] When the horizontal shaft 2 is constructed from the shaft 1, after the reinforcement support 6 for the wellhead is installed, the parent pile 3 located at the wellhead is installed.
Is cut, and as shown in FIG.
Excavation, and while installing the shoring 8 for each section 7,
Drill towards the tip. As for the shoring 8, the type is slightly different for each section, and the one having a square shape in a front view and the one having a gate shape are appropriately installed, and a wooden sheet is provided on a surface facing a wall surface of the ground. The shafts 2 that are adjacent to each other in the longitudinal direction are connected to each other by a shoring joint 8a. When the horizontal shaft 2 is constructed, a pipe roof 9 is provided along the wall of the ground around the installed supports 8... To reinforce the wall of the ground and prevent its collapse. are doing. In addition, what is shown with the code | symbol 10 in FIG. 1 is an existing sewer pipe. [0004] However, the method for constructing the horizontal shaft has the following inconveniences. That is, the excavation cross section of the horizontal shaft 2 is divided into a large number (24 divisions), and the shoring 8 is installed for each section 7. That is, since the shoring material is subdivided, the shoring 8 Since the looseness of the shoring joints 8a connecting each other is accumulated, the supporting force is easily reduced, and the digging cross section becomes small, so that it is difficult to set the digging gradient to a stable gradient. Since the bearing capacity is reduced, there is a possibility that the ground surface will sink. Further, as described above, since the support material is subdivided, the supports 8 are densely packed in the excavated shaft, so that the inner wall of the shaft 2 is covered with reinforced concrete. Since it is difficult to insert and assemble a long horizontal reinforcing bar at the time of construction, the horizontal reinforcing bar must be shortened, and the joints of the horizontal reinforcing bar increase. In addition, since the supports 8 are densely packed in the excavated horizontal shaft, when the lining with the reinforced concrete is performed, not only is the formwork, box removal, etc. complicated, but also the work efficiency after the lining is reduced. It will decrease significantly and the construction period will be prolonged. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of constructing a cross shaft capable of increasing a space between supports and preventing a decrease in support force of the supports. And [0007] In order to achieve the above object, a cross shaft construction method according to claim 1 of the present invention divides a cross section when excavating a cross shaft into upper and lower parts, and After excavating the excavated cross section, an upper support is installed in this upper excavation pit, and then a girder supporting the upper support is inserted into the upper excavation pit in the longitudinal direction of the upper excavation pit, and The upper girder is supported by the girder, and then the lower excavation section is excavated.
Driving a pile from the ground surface into the tip of the horizontal shaft
And the support provided at the base end of the shaft, supporting the girder
It is characterized by having In the method for constructing a cross shaft according to claim 1 of the present invention,
An upper load installed on the upper excavation pit is supported by a girder inserted into the upper excavation pit, so that an upper load acting on the upper support is received by the girder. As a result, the number of shoring works is reduced as compared with the related art, the excavation section is widened, and a decrease in the supporting force of the shoring works is prevented. Also, by reducing the number of shoring, the space between the shorings is expanded, so that a relatively large machine can be introduced, which reduces the burden on the workers and greatly shortens the construction period. Plan. Furthermore, since the number and spacing of the supports to be installed can be reduced, when the inner wall of the horizontal shaft is reinforced with reinforced concrete, it is easy to assemble reinforcing bars, formwork, remove boxes, and improve work efficiency. I do. Further, the pile that is driven from the ground surface to the tip of the Adit, by supporting the digits through by the support provided to the base end portion of the adit, the upper load acting on the upper shoring Be sure to receive by the girder. An embodiment of the cross shaft construction method of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing the horizontal shaft 2,
FIG. 2 is a sectional view taken along the line AA in FIG. 1. In order to construct the cross shaft 2 shown in these figures, the excavated section is divided into upper and lower sections, and after excavating the upper excavated section, Excavate the excavation section. That is, first, reinforcement support 1
0 is set and the upper excavation work stage is assembled.
In addition, a mountain stop parent pile 11 is constructed on the back side of the reinforcing support 10. Next, after the pit entrance is viewed from the front, the upper right side of the mountain retaining stake 11 is cut, and a space necessary for the erection work is secured, and excavation is performed by a mini backhoe or the like. In this excavation, a portion indicated by a reference numeral P1 in FIG. 2 is excavated. After this excavation, the support material 13 constituting the right side portion of the upper first support JS1 is built. [0012] As shown in FIG.
The steel members 14 are assembled in a gate shape, and the corners on the wall surface side of the horizontal shaft 3 are reinforced by diagonal members 15. Shoring material 1
3 among the steel materials 14 constituting the right side, the right vertical steel material 14
As shown in FIG. 3, a receiving member 16 protruding to the left is fixed to the lower end of the left side by bolts and nuts. Also, as shown in FIG. A pair of receiving members 16, 16 protruding on both left and right sides are fixed by bolts and nuts. The receiving members 16 are fixed at the height position of the steel member 14. [0013] Next, after cutting the upper mountain left parent stake 11 on the left side of the upper stage, a space necessary for the erection work is secured, and excavation is performed by a mini backhoe or the like. This excavation excavates a portion indicated by reference numeral P2 in FIG. Then, after this excavation, the support material 17 constituting the left portion of the upper first support JS1 is built. The support material 17 is formed by assembling steel materials 14 in a gate shape, like the support material 13.
The corners on the wall side of the horizontal shaft 3 are reinforced by diagonal members 15, and receiving members 16 are fixed to two vertical steel members 14 constituting the supporting member 17, similarly to the supporting member 13. I have. Next, if the stake 11 on the center left of the upper stage is cut and the soil quality is confirmed and stable, the stake 11 on the center right of the upper stage is cut and necessary for erection. A sufficient space is secured, and cutting is performed in the same manner as above. This cutting excavates portions indicated by reference numerals P3 and P4 in FIG. After this excavation, the supporting material 18 constituting the central portion of the upper first supporting structure JS1 is built. This support material 18
Is formed by assembling steel members 14 in a substantially T-shape. Both ends of the horizontal steel member 14 are vertically connected to the respective horizontal steel members 14 of the support members 13 and 17 as shown in FIG. A steel member 14 is fixed by bolts and nuts. Further, a pair of receiving members 16, 16 protruding to the left and right sides are fixed to the lower end portion of the vertical steel material 14 by the bolts and nuts. In this way, by excavating the portions indicated by reference numerals P1 to P4 and building the upper first support JS1 including the support materials 13, 17, and 18, the excavation section at the entrance of the horizontal shaft 2 is obtained. After the construction of the upper berth is performed, similarly, the upper berth 20 is formed by digging the upper berth, and the upper second shoring JS2 to the upper ninth shoring S9 are sequentially built, and the horizontal pit is formed. The construction of the upper excavation pit 20 in the second upper stage is completed.
Each of the upper second shoring JS2 to the upper ninth shoring S9 has the same configuration as the upper first shoring JS1, and a receiving member 16 is fixed to the lower end of the vertical steel member 14, respectively. I have. In addition, the support structures adjacent in the length direction of the horizontal shaft 2 are connected to each other by a cross bracing 21. After the completion of the construction of the upper excavation pit 20 as described above, eight continuous girder 2
2 are inserted in the longitudinal direction of the upper excavation pit 20. .. Are connected to the upper first support JS1 to the upper ninth.
The support S9 is temporarily received and supported, and is formed of, for example, H steel. In the case where the continuous girder 22 is inserted, the continuous girder 22 is inserted directly below the receiving members 16 fixed to the upper first shoring JS1 to the upper ninth shoring S9, and these receiving members 16 are placed on the continuous girder 22. By doing
The shoring JS1 to the upper ninth shoring S9 are temporarily supported from below. As shown in FIG. 1, the left end of each of the stringers 22..., That is, the end on the entrance side of the shaft 2, is made of a steel material provided at the entrance of the shaft 2. The right ends of the stringers 22, that is, the ends on the tip side of the horizontal shaft 2 are supported by piles 24, respectively. These piles 2
Reference numerals 4 are driven into the tip of the horizontal shaft 2 from the ground surface, and are constructed as follows. That is, first, the ground near the tip of the horizontal shaft 2 is improved. This ground improvement is performed by a method called “column jet grouting method”. In this method, ultra-high pressure water with air is rotated and injected into the ground to cut the ground, discharge the slime to the surface, fill the hardening material at the same time, and turn the columnar consolidated body vertically. In the present embodiment, the solidified body row 25 composed of a large number of solidified bodies formed so as to slightly overlap each other in a direction perpendicular to the paper surface in FIG. To 2
The ground is improved by slightly overlapping the rows. Then, of the solid row 25, the shaft 2
The piles 24 are driven into the consolidated body row 25 located at the entrance side of the or the solidified body row 25 is drilled,
The pile 24 is inserted into each of the boring holes and driven into the ground further below. When driving piles 24...
. Are driven into contact with the tips of the piles 24, and the stringers 22 are connected and fixed to the piles 24, respectively. Therefore, since both ends of the girder 22 are supported by the support body 23 and the pile 24, the upper first shoring JS1 to the upper ninth shoring S9 are reliably supported by the girder 22. In this embodiment, the pile 24 is driven after the ground is improved. However, when the ground is hard, the pile 24 may be driven directly without performing the ground improvement. The driving of the pile 24 may be performed at any time as long as it is before the completion of the construction of the upper excavation pit 20, and may be performed before the construction of the lower excavation pit 26 even after the construction of the upper excavation pit 20 is completed. It may be done at any time. Now, as described above, the upper excavation pit 20
If the upper first shoring JS1 to the ninth shoring S9 built in the tent are temporarily supported by the girder 22, the reinforcing shoring 27 is installed at the lower part of the wellbore, and the lower excavation work stage is assembled. Then, after cutting the lower right retaining pile 11 on the right side of the lower stage, a space necessary for the erection work is secured, and excavation is performed by a mini backhoe or the like. This excavation excavates the portion indicated by reference numeral P5 in FIG. Then, after this excavation, the support material 28 constituting the right side portion of the lower first support KS1 is built. The support member 28 is formed by assembling the steel members 14 in a substantially rectangular shape when viewed from the front. As shown in FIGS. 3 and 4, the upper ends of the pair of vertical steel members 14 Bolts and nuts are joined and fixed to the lower end surfaces of the pair of vertical steel materials 14 of the work material 13, and the horizontal upper steel material 14 is bolted to the lower end side surfaces of the pair of vertical steel materials 14 of the support material 13. And is fixedly joined by a nut. Then, after cutting the lower left mountain retaining pile 11, a space necessary for erection work is secured, and excavation is performed by a mini backhoe or the like. This excavation
The portion indicated by the reference numeral P6 is excavated. And after this excavation,
Shoring material 3 that constitutes the left part of the lower first shoring KS1
Build 0. The support material 30 is the support material 28
In the same manner as described above, the steel materials 14 are assembled in a square shape, and the pair of vertical steel materials 14 are joined and fixed to the end surfaces of the lower end portions of the pair of vertical steel materials 14 of the support material 17 with bolts and nuts. The horizontal upper steel member 14 is joined and fixed to the lower end side surfaces of the pair of vertical steel members 14 of the support member 17 with bolts and nuts. Next, each of the stakes 11 on the lower left side and the lower right side is cut to secure a space necessary for the erection work, and cutting is performed in the same manner as described above. This cutting excavates portions indicated by reference numerals P7 and P8 in FIG. Then, after this excavation, the support material 31 constituting the central portion of the lower first support KS1 is laid. This support material 31 is formed by assembling steel materials 14 in a substantially E-shape.
Both ends of the horizontal upper steel material 14 are supported by the supporting material 1.
Each of the vertical steel members 3 and 17 is fixed to the lower end side surface by bolts and nuts. Further, both ends of the horizontal steel material 14 below the support material 31 are fixed to ends of the horizontal steel material 14 below the support materials 28 and 30 by bolts and nuts. Further, the butted ends of the upper horizontal steel material 14 of the support material 31 are fixed to the lower end side surfaces of the vertical steel material 14 of the support material 18 by bolts and nuts. 14 are butted and fixed by bolts and nuts. In this way, by excavating the portions indicated by reference numerals P5 to P8 and building the lower first shoring KS1 including the shoring materials 28, 30, and 31, the digging section at the entrance of the horizontal shaft 2 is obtained. After constructing the lower berth, similarly, the lower berth KS2 to the lower ninth berth KS9 are sequentially built while the lower berth is advanced to form the lower excavation pit 26, and the horizontal shaft is formed. The construction of the lower excavation pit 26 at the lower stage of 2 is completed. The lower second support KS2 to the lower ninth support KS
Each of 9 has the same configuration as the lower first shoring KS1, and the shorings adjacent in the length direction of the horizontal shaft 2 are connected to each other by a cross strut 21. In addition, at the time of the construction of the upper excavation pit 20 and the lower excavation pit 26, a pipe roof 9 is provided along the wall of the ground around the installed shoring to reinforce the wall of the ground, The collapse is prevented. After that, the inner wall of the horizontal shaft 2 is reinforced with reinforced concrete. As described above, the supports installed in the horizontal shaft 2 are connected to the upper first supporting structures JS1 to JS1 by the girder 22.
Since the upper load acting on the upper ninth shoring JS9 is received, the number and intervals of the shorings to be installed can be reduced as compared with the related art. Therefore, at the time of lining with the reinforced concrete, assembling of a reinforcing bar, formwork, box removal, and the like are easy, work efficiency is improved, and the construction period can be shortened. In this embodiment, since the upper load acting on the upper first shoring JS1 to the upper ninth shoring JS9 is received by the girder 22, the number of the shoring is reduced as compared with the prior art. Naturally, the number of joints between the supports is reduced, and therefore, the accumulation of looseness of the joints is also reduced.Moreover, by reducing the number of supports, the excavated cross section can be widened. In addition, since a safe excavation gradient can be ensured according to the excavation target soil, a decrease in the support force of the shoring work is not caused, and therefore, subsidence of the ground surface can be prevented. Further, by reducing the number of the supports, the space between the supports is expanded, so that a relatively large-sized machine can be introduced in both excavation and support installation. Can be reduced, and the construction period can be significantly reduced. Also, the girder 22 is supported by the pile 24 driven into the tip of the shaft 2 from the ground surface and the support 23 provided at the base end of the shaft 2. The bridge girder 22 can reliably receive the upper load acting on the upper first shoring JS1 to the upper ninth shoring JS9, and thus can reliably prevent the ground surface from sinking. As described above, according to the first aspect of the present invention,
According to the horizontal shaft construction method, the upper shoring installed in the upper digging pit is supported by the girder inserted into the upper digging pit, so that the upper load acting on the upper shoring is subjected to the girder. Received by Therefore, compared to the past,
The number of supports can be reduced, and naturally, the number of joints between the supports decreases, and therefore, the accumulation of looseness of the joints also decreases. Since the cross section can be widened and a safe excavation gradient can be secured in accordance with the excavated soil, the supporting force of the shoring does not decrease, and therefore, the settlement of the ground surface can be prevented. Since the space between the supports is increased by reducing the number of the supports, a relatively large-sized machine can be introduced for both excavation and support installation. Can be reduced, and the construction period can be significantly reduced. Further, since the number and intervals of the shorings to be installed can be reduced as compared with the conventional case, when the inner wall of the horizontal shaft is reinforced with reinforced concrete, it is easy to assemble the reinforcing bar, form the frame, and remove the box. Therefore, the working efficiency is improved and the construction period can be shortened. Also, the girder is supported by the pile driven into the tip of the cross shaft from the ground surface and the support provided at the base end of the cross shaft, and the upper girder is supported by the girder. It is possible to reliably receive the upper load acting on the work, and therefore, it is possible to reliably prevent the settlement of the ground surface.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a cross shaft, showing one embodiment of a cross shaft construction method of the present invention. FIG. 2 is a sectional view taken along line AA in FIG. FIG. 3 is an enlarged view of an X circle portion in FIG. 2; FIG. 4 is an enlarged view of a Y circle portion in FIG. 2; FIG. 5 is an enlarged view of a Z circle portion in FIG. FIG. 6 is a side sectional view of a horizontal shaft, showing an example of a conventional horizontal shaft construction method. FIG. 7 is a front view of the horizontal shaft. [Description of Signs] 2 Horizontal shaft 20 Upper excavation shaft 22 Continuous girder 23 Support body 24 Pile 26 Lower excavation shaft JS1 to JS9 Upper support KS1 to KS9 Lower support

Claims (1)

(57) [Claims] [Claim 1] The excavation cross section for excavating the horizontal shaft is divided into upper and lower parts, and first, the upper excavation section is excavated, and then an upper support is installed in the upper excavation pit. Then, a girder supporting the upper support was inserted into the upper excavation pit in the longitudinal direction of the upper excavation pit to support the upper support on the girder, and then a lower excavation section was excavated. Later, a lower support was installed for this lower excavation.
Driving a pile from the surface,
A method for constructing a cross shaft, comprising: supporting a continuous girder with a holding body .