JPH0647821B2 - Construction method of continuous underground wall and steel panel for continuous underground wall construction - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a construction method for a continuous underground wall and a steel panel used as a wall material for the construction method.

[Prior art]

In the conventional general continuous underground wall construction method, the following work was required for each of the leading element and the trailing element. Leading element Drilling the leading element. Installation of interlocking pipes and joint pipes. Reinforcement basket construction. Placing concrete. Trailing element Drilling trailing element. Pulling out the joint box. Reinforcement basket construction. Placing concrete.

[Problems to be Solved by the Invention]

Therefore, there were the following problems. (1) When constructing a pile with a large depth, for example, if the size of the reinforced basket is 1 m in width, 6.3 m in length, and 50 m in height, a large crane of 150 t class is required for the construction. It was (2) 100m when using a 150t class large crane
A working yard of about × 200m was required. (3) As a yard for constructing a reinforcing bar basket, a raw material storage area, a raw material processing storage area, a reinforcing bar basket assembly stand, a reinforcing bar basket temporary storage area, etc. were required, so it was necessary to secure a role of about 4,500 m ² . (4) Since concrete is spliced in muddy water, it was difficult to secure water stop near the horizontal joint. (5) Due to the design, it was necessary to install support work during excavation. (6) When excavating the vertical piles, a drainage system for treating the water accumulated on the bottom was required, and the pump had to be moved according to the excavation conditions, resulting in poor workability. (7) In the improvement of the bottom ground by boring from the ground, sometimes problems of boiling and heaving occurred depending on the construction accuracy and soil condition. (8) Reinforcing bar processing and manufacturing of reinforcing bar baskets are performed at the construction site, so it was necessary to collect skilled workers such as reinforcing bar workers at each site. (9) Due to the reinforced concrete, the wall thickness of the vertical pile tended to be considerably thicker by design. An object of the present invention is to make it possible to construct a large-depth continuous wall efficiently, easily, and with good workability without the above problems.

[Means for Solving the Problems]

In the construction method of the present invention, a vertically long steel panel is used as the wall material. This steel panel has a hollow double wall structure, that is, a box shape with steel plates inside and outside and a plurality of steel ribs between them,
The box-shaped interior is filled with a lightweight filler, or a cavity is formed to give buoyancy. With this steel panel floating in the muddy water of the excavation trench, the left and right ends and the upper and lower ends of the steel plates of the steel panels are connected by welding etc. After forming a steel double wall body of a desired shape to a predetermined depth, placing concrete between the outer periphery of the steel double wall body and the inner wall of the excavation groove or solidifying muddy water between them. And fix it. The steel panels are preferably staggered. After sunk to a predetermined depth, concrete can be poured between the steel plates inside and outside the box-shaped inside of the steel panel. If a box-shaped part is formed by the inner and outer steel plates and a plurality of steel ribs between them, and if an opening is provided in the outer steel plate protruding outside this box-shaped part, the outer circumference of the steel double wall body and excavation Concrete can be poured through the opening between the groove and the inner wall. Joints can be provided on the left and right edges of the steel plate inside and outside the steel panel.

[Action]

Steel panels can be manufactured at the factory up to the point where they are filled with lightweight filler, and can be installed as they are without any assembly work on site. Since the steel panel is given buoyancy by the lightweight filler or hollow part, it can be floated in muddy water to reduce the weight and can be easily installed using a small crane. Since the steel panels can be connected to each other by welding the steel plates inside and outside thereof, the workability is very good, and the water stopping property of the splice joint is also good. The structural performance is also improved due to the synergistic effect of the rigidity of the hollow double-walled steel panel and concrete.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is a perspective view of an example of a steel panel used in the construction method of the present invention. First, the steel panel 1 will be described. It has a form in which two steel sheet piles and a square steel pipe are integrated. That is, two vertically elongated steel plates (steel sheet piles) 3 and 4 each having a joint portion 2 having a U-shaped cross section on both left and right edges, and two steel ribs 5 on the left and right having the same vertical length are arranged in parallel. In a box shape, a box-shaped part (square steel pipe) 6 is formed in the center, and recesses 7 are formed on the left and right sides of the box-shaped part 6.
It is filled with foamed concrete 8 for giving reinforcement and buoyancy. The width of the outer steel plate 4 is larger than that of the inner steel plate 3 so that when the steel panel 1 is added to the left and right, the steel plate 4 has a cylindrical shape. In the steel panel 1 shown in the figure,
A large number of openings 9 are vertically provided at predetermined intervals on both left and right sides of the outer steel plate 4. This opening 9 is
As will be described later, the concrete filled in the left and right recesses 7 is for flowing out to the outside. This does not have to be provided on all the steel panels 1, and either the steel panels not provided at all or the left or right Some steel panels are provided only on the side. The foam concrete 8 is a concrete containing a large number of closed cells, and can be easily prepared by, for example, forming a foaming agent from foam, kneading it with cement milk, and curing it in the box-shaped portion 6. When ordinary concrete is used instead of the foamed concrete 8, a hollow portion 10 is formed in the concrete to give buoyancy. Further, although one box-shaped portion 6 is illustrated in the figure as an example, a plurality of box-shaped portions 6 may be connected to the left and right as shown in FIGS. 8 and 10. The steel panel 1 in any of the forms is manufactured in a factory, brought to an appropriate length in the field. FIG. 3 is an explanatory view showing an example of a work procedure of the construction method of the present invention,
FIG. 1 is a perspective view showing in detail the process in the middle thereof. In FIG. 3, as shown in (a), pre-excavation for the guide wall described later is performed by the power shovel 11, etc., and as shown in (b) and (c), the excavator 12 is repeatedly excavated, and (d) A ring-shaped groove 14 having a predetermined depth and containing muddy water 13 is excavated as described above. In the state where the steel panel 1 is suspended by the crane 15 as shown in (d), the joint portions 2 of the steel panels 1 are welded to each other, and the steel panels 1 are sequentially connected to the right and left, and the bottommost cylinder is connected. Form a double-barrel element 16 ₁ . Then, it is suspended in the crane 15 and floated in the muddy water 13. The steel panels 1 adjacent to each other in the circumferential direction are formed by connecting the recesses 7 to each other to form a vertically long cavity, but in the example shown in the drawing, the steel panel 1 having the opening 9 and the steel panel 1 having no opening or one side. Since the steel panel 1 which has only one of them is used together, a cavity 17 having the opening 9 and a cavity 18 having no opening 9 can be formed. Bottom cylindrical double body element
Only for 16 ₁ , the lower end of the cavity 17 having no opening 9 is sealed. Next, the lower end of the second steel panel 1 is welded to the upper end of the steel panel 1 of the lowermost cylindrical double-barrel element 16 ₁ as shown in (e), and the same applies to the second stage. While the steel panel 1 is being hung by the crane 15, the joint portion 2 is also connected to the left and right, and the cylindrical double-barrel element 16 ₂ in the second stage is added to add the cylindrical double-barrel element 16 ₁ in the second stage. 16 ₂ constitutes a double shell 16 which is a continuous cylindrical steel double wall body. In this case, the seams of the upper and lower steel panels 1 are arranged in a zigzag arrangement in consideration of strength, and the cavities 17 with the openings 9 and the cavities 18 without the openings 9 are respectively continuous in the vertical direction. . The double shell 16 is filled with water by pouring into the cavity 18 without the opening 9.
As shown in (f), the guide ring 19 (Fig. 1) is guided to the required depth to sink, and in this state, the cylindrical double-barrel element 16 ₃ of the third stage is added, and the same work is repeated.
As shown in (h), the double shell 16 formed by the cylindrical double shell element having the designed number of steps is sunk to a predetermined depth. The double shell
If the weight of 16 is such that it will naturally sink in the muddy water 13 only by its own weight, for example, give buoyancy from the outside with an air packer, or support it on the guide ring 19 and let it float in the muddy water 13. Keep it in the upright position and perform additional work. Further, with respect to the steel panel provided with the hollow portion 10 as shown in FIG. 2, water can be poured into the hollow portion 10 to settle it. In this case, the cavity 18 without the opening 9 is not always necessary. When the settling to the predetermined depth is completed as described above, the opening 9
Drain the water in the empty cavity 18 and, if necessary, the cavity 18
Concrete 20 is placed inside as shown in Fig. 4 to strengthen the rigidity. Reference numeral 21 is a guide wall. Further, concrete is poured from the tremie pipe 22 into the cavity 17 having the opening 9, the concrete is caused to flow out through the opening 9, and the concrete is injected between the double shell 16 and the inner wall of the groove 14 and in the cavity 17.
Concrete 23 is poured as shown in the figure, or muddy water in these is solidified, and the double shell 16 is fixed in the ground.
As a result, a continuous cylindrical underground wall 24 having a steel double wall structure is constructed. Next, as shown in FIG. 6, a horizontal boring device 26 for ground improvement and a pipe 27 to the ground are installed from a space portion (cavity) 25 left at a required location of the continuous underground wall 24, Ground improvement of the bottom 28 surrounded by the continuous underground wall 24. After this, as shown in FIG. 7, the ground surrounded by the continuous underground wall 24 is excavated from the ground. In this case, unmanned construction can be performed by attaching the vertical continuous earth discharging device (trerelifter) 29 and the automatic excavator 30 to the steel inner wall of the continuous underground wall 24. Regarding the treatment of water on the bottom plate 28, a drainage pump 31 is installed in the space 25.
The strainer installed on the inner steel wall of the continuous underground wall 24
Aspirate through 32. Further, an elevator 33, stairs, or the like can be provided on the steel inner wall of the continuous underground wall 24. In the above-mentioned embodiment, after the ring-shaped continuous groove 14 was excavated, the steel panels 1 connected in a cylindrical shape were successively sunk into the groove 14, but the groove was not continuous in the ring shape from the beginning. After excavating by dividing the circumference with the steel panel 1 to a predetermined depth in the excavated groove, the excavation of the groove and the deposition of the steel panel 1 are repeated alternately to finally make a cylindrical shape. There is also a method. Fig. 8 and Fig. 9 show an example of this. After excavating a groove 34 having a required width, the first steel panel 11 suspended by a crane is inserted into the groove 34, and the first steel panel ₁₁ is inserted into muddy water. And fix it to the required depth with, for example, a guide ring 35, and connect the next second steel panel 1 ₂ to the left or right side at the joint portion 2, and in the same way the 3rd steel panel Take 1 to ₃ . In this way, the linked three steel panel 1 ₁ -
1 ₃ as 1 element, sequentially subjoin the following elements thereon. After sinking to a predetermined depth, both sides of the steel panels 1 _1, 1 ₃ of the joint portion 2 mortar around the jacket 36
Is installed to solidify the muddy water in the gap 37 surrounded by the mortar jacket 36. This constitutes a steel double wall for one section. The shield 38 of the mortar jacket 36 is
The suspension jig 39, the suspension rope 40, and the crane hook 41 are used and suspended until the muddy water solidifies. After mud caking and drilling the next adjacent groove, this in the same manner as described above connecting the steel panel 1 ₁ to 1 ₃ in the groove, further subjoin above. In this case, the already-installed steel double wall body for one section is connected by the joint portion 2. Below, trench excavation and steel panels 1 ₁ to 1
_The continuous connection and addition of ₃ are repeated alternately to build a continuous underground wall in a cylindrical shape. Similarly, FIGS. 10 and 11 show a method by circumferential division,
Processing of the joint portion 2 is different from the example shown in FIGS. 8 and 9. That is, the steel panels at both ends ₁ 1, _{1 3} of the joint section 2
Then, grease or the like is filled therein to prevent solidification of muddy water here, and after the steel double wall body for one section is constructed, the muddy water 42 around the entire circumference is solidified. After fixing the steel double wall,
As shown in Fig. 11, the joint parts 2 of the steel panels 1 ₁ and 1 ₃ at both ends
With respect to the above, the cleaning machine 43 such as a jet cleaner is attached and moved using it as a guide, and the muddy water solidifying material around the joint portion 2 is removed. When it is necessary to maintain the excavated part as it is for a long time due to some trouble during excavation of the trench, or when the excavated part is likely to collapse, a gelling agent that releases the gel state by stirring (So-called chemical gel medicine) should be used to gel and stabilize mud water. The gelled mud is stirred with a stirrer at appropriate times to return it to the original mud. In this case, the stirrer can be attached to the steel double wall. The present invention is not limited to the case of constructing a continuous underground wall having an overall cylindrical shape, but can be widely applied to the case of constructing a continuous underground wall having another shape such as a rectangle or an ellipse.

【The invention's effect】

The effects of the present invention are listed below. A hollow double-walled steel panel is used instead of a heavy reinforced steel basket, and this is floated in muddy water to be replenished, so a crane of 150t class was conventionally required. But you can work,
It is possible to efficiently construct a continuous underground wall with a large depth, and the work space is small. Steel panels can be manufactured at the factory and can be added one by one as they settle in muddy water, so there is no need for a large work space such as on-site assembly of the reinforcing bar basket. It can be reduced by about 50%. The hollow part of the constructed wall can be used to install drainage equipment and horizontal boring equipment for improving the bottom plate. Steel panels are manufactured at the factory, so walls of uniform quality are produced. Since the joint part can be completely welded, it is possible to secure complete waterproofing as a connecting wall. Since the steel panel can be manufactured as a separate process from the on-site work, the process at the construction site can be reduced to about half. Elevating equipment such as stairs and elevators can be installed accurately and reliably using the steel inner wall of the continuous underground wall. If there is a wall / frame joint, it can be placed in place. The stress applied to the wall is also transmitted in the circumferential direction of the steel connecting wall,
The whole structure will be stressed, and excavation can be done in a short period of time without using a girder or a bulge.

[Brief description of drawings]

FIG. 1 is a perspective view of an example of the construction method of the present invention, FIG. 2 is a perspective view of an example of a steel panel according to the present invention, and FIGS. 3 (a) to (h) are examples of work procedures of the construction method of the present invention. Fig. 4 is a cross-sectional view of the concrete pouring state therein, Fig. 5 is a plan view showing the state after concrete pouring and mud solidification, and Fig. 6 is a bottom plate after continuous underground wall construction. Sectional view showing a ground improvement state, FIG. 7 is a sectional view showing a vertical pile excavation state, FIGS. 8 and 9 are plan views and sectional views of another example of the method of the present invention,
10 and 11 are plan views of still another example. 1 ... steel panel, 2 ... joint part, 3,4 ... inside and outside steel plates, 5 ... steel rib, 6 ... box part, 8 ... foam concrete, 9 ... opening part, 10 ... Hollow part, 13 …… Muddy water, 14,
34 …… Groove.

Front Page Continuation (72) Inventor Susumu Tsuruoka 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Intra-company group (56) Reference JP-A-63-70713 (JP, A)

Claims (5)

[Claims] 1. A light filling material is filled into a box-shaped interior of a vertically long steel panel having a box shape made of inner and outer steel plates and a plurality of steel ribs therebetween, or a hollow portion is formed to give buoyancy, In a state where the steel panel is floated in the muddy water of the excavation groove, the left and right ends and the upper and lower ends of the steel plates of the steel panels are connected by welding or the like, so that the steel panel is settled while sequentially adding the left and right and the upper and lower sides. After the steel double-walled body having a desired shape is laid down to a predetermined depth, concrete is placed between the outer periphery of the steel double-walled body and the inner wall of the excavation groove or the muddy water between them is solidified. Construction method of continuous underground wall, which is characterized by 2. The method for constructing a continuous underground wall according to claim 1, wherein the steel panels are added while staggered in a staggered manner. 3. A steel double wall body, which is sunk to a predetermined depth, and then concrete is placed between the steel plates inside and outside the box-shaped inside of the steel panel.
Construction method of continuous underground wall described in. 4. A vertically long steel panel in which a box-shaped portion is formed by inner and outer steel plates and a plurality of steel ribs between them, and an opening is formed in the outer steel plate protruding outside the box-shaped portion. Then
The box-shaped part is filled with a lightweight filler, or a hollow part is formed to give buoyancy, and the steel panel is floated in the muddy water of the excavation trench, and the left and right ends of the steel panel and the top and bottom of the steel plate By connecting both ends by welding or the like, steel panels are successively added to the left and right and top and bottom while sinking to form a steel double-walled body of a desired shape, and after being laid down to a predetermined depth, the steel double-walled body A method for constructing a continuous underground wall, characterized in that concrete is placed through the opening between the outer circumference and the inner wall of the excavation trench. 5. A box-shaped portion is formed by connecting two vertically long steel plates inside and outside with a plurality of steel ribs, and an opening is formed in an outer steel plate protruding outside the box-shaped portion. Filling the inside with a lightweight filler or forming a cavity to give buoyancy,
A steel panel for constructing a continuous underground wall, characterized in that joint portions are provided on both left and right edges of the inner and outer steel plates.