JPH056606B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an oblique pile driving method in which steel pipe piles are driven diagonally from the sea using an offshore workbench.

[Prior art] In order to construct a sea berth, which will serve as a distribution base for the purpose of storage management and receiving/receiving operations of LPG, petroleum, chemicals, etc., foundation piles are driven under the seabed.

There are two types of pile driving: vertical piles and diagonal piles, but in the case of vertical piles or diagonal piles, if the sediment layer is thick and the specified pull-out resistance can be obtained, the direct driving method is used. Can be constructed. However, if the sediment layer is thin and the sediment layer alone does not have enough root depth to provide the required pull-out resistance, and if it is necessary to provide the rock with pull-out resistance, it is not possible to use the direct hammering method. This is difficult and depends on the method of driving piles into the bedrock.

Regarding the diagonal pile driving method into bedrock, the present applicant has previously disclosed the method in Japanese Patent Application Laid-Open No. 58-213917 and Japanese Patent Application Laid-open No. 58-213918, and furthermore, a ring bit is used to prevent collapse at the pile tip. The construction method is known. To explain this with reference to Figures 16 to 25, A is a sedimentary layer such as silt and sand layer, B is
is a rock such as granite, and the steel pipe pile 1 is placed at a predetermined inclination angle using a pile driving tower and a pile driver installed on an offshore workbench (not shown).
Drive until it reaches (Figure 16). Next, set the excavator M1 on the pile driving tower, and move the excavator M1 to the steel pipe pile 1.
excavate the sedimentary layer A in the steel pipe pile 1 through the
Figure 7). Next, excavator M1 is removed from the pile driving tower (Figure 18). Next, set the ring bit excavator M2 on the pile driving tower, pass the ring bit excavator M2 through the steel pipe pile 1, and use the ring bit 2 to excavate rock B to a certain depth (approximately half of the ring bit 2 is submerged) (Figure 19). . Next, the ring bit 2 is separated from the attachment/detachment device 3, and the ring bit excavator M2 is removed (FIG. 20). If it is predicted that ring bit 2 alone cannot prevent the collapse of the borehole, mortar C is filled between ring bit 2 and rock B and inside ring bit 2 (21st
figure). Next, the excavator M3 is set on the pile driving tower, and the excavator M3 is passed through the steel pipe pile 1 to excavate the bedrock B to a predetermined depth (FIG. 22). Next, excavator M3 is removed (Fig. 23). Next, set the anchor pile setting jig M4 with the anchor pile 4 attached to the pile driving tower, and attach the anchor pile setting jig M4 to the steel pipe pile 1.
After processing the slime with the mortar injection pipe 5, insert the mortar C into the anchor pile 4.
(Figure 24). Finally, the anchor pile erection jig M4 is removed, mortar C is filled inside the steel pipe pile 1 to such an extent that the anchor pile 4 is hidden, and the steel pipe pile 1 and the bedrock B are integrated via the anchor pile 4.

By the way, in this method, excavation inside the steel pipe pile (Fig. 17) → ring bit excavation (Fig. 19) →
Rock excavation (Figure 22) and three stages of excavation will be carried out. 3
Requires types of excavators M1, M2 and M3;
Furthermore, an anchor pile erection jig M4 is required,
It takes longer to change the setup of excavators and jigs. Therefore, there is a higher risk of the borehole collapsing, and furthermore, the ring bit 2 alone cannot completely prevent collapse, and therefore, there is a problem in that it is necessary to take delicate measures to prevent collapse.

[Object of the Invention] Therefore, an object of the present invention is to provide a diagonal pile driving method that prevents collapse of the wall of an excavation hole and shortens setup time.

[Structure of the Invention] The diagonal pile driving method according to the present invention involves driving steel pipe piles at a predetermined inclination angle into the sedimentary layer until they reach the bedrock using a pile driving tower and a pile driver installed on an offshore workbench.
Next, an excavator having a diameter expanding bit attached to the tip of the excavating rod via a telescoping jack and an anchor pile attached to the excavating rod via a chuck device is set on the pile driving tower, and the excavator is passed through the steel pipe pile. Excavate the bedrock following the sedimentary layer by enlarging the diameter of the diameter expansion bit to make the excavation diameter larger than the diameter of the anchor pile, interrupting the excavation at the required depth, and contracting the expansion jack by reducing the diameter of the diameter expansion bit. Push the excavator forward to push the anchor pile to the bottom of the hole,
This process of digging the diameter expansion bit and pushing in the anchor pile is repeated, and when the anchor pile reaches a predetermined depth in the rock, the anchor pile is separated from the chuck device, the excavator is removed, and the mortar injection pipe is inserted through the steel pipe pile. Mortar is filled between the anchor pile, the bedrock, and the steel pipe pile, and inside the anchor pile and the steel pipe pile, so that the steel pipe pile and the bedrock are integrated through the anchor pile.

[Operations and Effects of the Invention] Therefore, since the wall of the borehole can be always held by the anchor pile, collapse of the wall of the borehole can be completely prevented, and since excavation is carried out with one type of excavator, Setup time can be reduced,
Economical. Furthermore, in the case of a structure in which the anchor pile is permanently installed, the erection time can be omitted and the anchor pile can be reliably erected at the bottom of the excavation hole.

[Examples] Examples of the present invention will be described below with reference to the drawings.

Figures 13-15 show an excavator used in carrying out the present invention. A diameter-expanding bit 13 is attached to the lower end of the excavator rod 11, which is movable downwardly in the excavator and is indicated by 10 in its entirety, via a telescoping jack 12. Chuck device 1 provided on rod 11
5 and a shoe 17 provided on the telescopic jack 12 that can be expanded and contracted in the radial direction by an actuator 16, and the diameter expanding bit 13 can be expanded and contracted in the radial direction by the actuator 14. . The stabilizer 18 is configured to be expandable and contractible in the radial direction, and maintains the position of the center of excavation relative to the steel pipe pile 1 during excavation. Therefore, the diameter of the expanding bit 13 is expanded to excavate the lower part of the anchor pile 4 (the 13th
(Fig. 14), the inner part of the anchor pile 4 can be excavated by reducing the diameter (Fig. 14). Also show 1
7 is reduced in diameter, the chuck device 15 is opened, the anchor pile 4 is separated from the excavator 10, and the excavator 10 can be pulled up (FIG. 15).

1 to 12 show one embodiment of the present invention.

A steel pipe pile 1 is driven into the sedimentary layer A at a predetermined inclination angle using a pile driving tower and a pile driver installed on an offshore workbench (not shown) until it reaches bedrock B (the first
figure). Next, set the excavator 10 on the pile driving tower and pass the excavator 10 through the steel pipe pile 1. For example, if the inner diameter of the steel pipe pile 1 is 1500 mm and the outer diameter/inner diameter of the anchor pile 4 is
In the case of 1100 mm/1072 mm, the excavation diameter of the diameter expanding bit 13 is expanded to 1300 mm, and the sedimentary layer A in the steel pipe pile 1 is excavated while advancing the excavator 10 (Fig. 2). Next, advance excavation of the rock B is started while the diameter expansion bit 13 is kept expanded (FIG. 3). Then the required depth, e.g.
After drilling 500mm, stop drilling and expand the diameter bit 13.
The diameter of the excavation was reduced to 1000 mm, and the telescopic jack 12
(Fig. 13), apply the weight of the excavator 10 to the anchor pile 4, and move the anchor pile 4 to the excavation hole D.
(Figure 4). Next, the process of drilling the diameter-expanding bit 13 with its diameter reduced and pushing the anchor pile 4 is repeated until the collapse of the excavated hole D stops (FIGS. 5 and 6). Once the collapse of borehole D has stopped,
Excavation of the diameter expansion bit 13 is expanded to 1300 mm and preliminary excavation is carried out (Fig. 7), and this preliminary excavation and pushing of the anchor pile 4 are repeated until the required depth is reached, and the excavation is completed (Fig. 8). Next, the excavation diameter of the diameter expansion bit 13 is reduced to 1000 mm, the telescopic jack 12 is contracted, and the weight of the excavator 10 is applied to the anchor pile 4, and the anchor pile 4 is pushed to the bottom of the excavation hole D (Fig. 9). . Next, the shaft 17 (FIG. 13) is reduced in diameter, the chuck device 15 is opened, the anchor pile 4 is separated, and the excavator 10 is removed (FIG. 10). Next, after performing slime treatment, mortar is injected (Fig. 11), and mortar C is injected between the anchor pile 4 and the rock B and the steel pipe pile 1, and into the anchor pile 4 and the steel pipe pile 1.
is integrated with bedrock B via anchor pile 4 (Fig. 12).

[Summary] As explained above, according to the present invention, the steps of expanding the diameter of the diameter-expanding bit to perform preliminary excavation, reducing the diameter of the diameter-expanding bit and pushing the anchor pile into the excavation hole are repeated,
Since the wall of the borehole can be held in place at all times with anchor piles, collapse of the borehole wall can be completely prevented, and since excavation is performed with one type of excavator, setup time can be reduced. . Furthermore, since the anchor pile can be erected with an excavator, in the case of a structure with a permanent anchor pile, the erecting time can be omitted and the anchor pile can be reliably erected at the bottom of the excavation hole. I can do it.

[Brief explanation of the drawing]

Figures 1 to 12 are diagrams showing the work process of the diagonal pile driving method according to the present invention.
The figure shows the preliminary excavation start process, Figure 4 shows the diameter expansion bit diameter reduction and anchor pile pushing process, Figures 5 and 6 show the excavation and anchor pile pushing process, and Figure 7 shows the diameter expanding excavation process. Figure 8 shows the completed state of excavation, Figure 9 shows the diameter expansion bit diameter reduction and anchor pile pushing process, Figure 10 shows the excavator removal process, and Figure 10 shows the excavation machine removal process.
Figure 1 shows the slime treatment and mortar injection process.
Figure 2 shows the completed state, Figures 13 to 15
The figures show the excavator used to carry out the present invention, Fig. 13 shows the excavation machine when expanding the diameter, Fig. 14 shows the excavation machine inside a pipe, Fig. 15 shows the excavator pulling up the excavator for separating the anchor pile, and Fig. 16 shows the excavator used to carry out the present invention. Figures 1 to 25 are diagrams showing the work process according to the conventional construction method. The figure shows the ring bit excavation process, Figure 20 shows the ring bit separation and excavator removal process, Figure 21 shows the mortar injection process, Figure 22 shows the rock excavation process, and the second
Fig. 3 shows the excavator removal process, Fig. 24 shows the anchor pile erecting process, and Fig. 25 shows the completed state. A...Sedimentary layer, B...Bedrock, C...Mortar,
D... Excavation hole, 1... Steel pipe pile, 4... Anchor pile, 5... Mortar injection pipe, 10... Excavator,
11...Drilling rod, 12...Telescopic jack, 1
3... diameter expansion bit, 15... chuck device.

Claims (1)

[Claims] 1. In the diagonal pile driving method, in which piles are driven diagonally from the sea to the bottom of the seabed, steel pipe piles are driven at a predetermined angle of inclination using a pile driving tower and a pile driver installed on an offshore work platform until they reach the bedrock. Then, an excavator with a diameter expanding bit attached to the tip of the excavation rod via a telescoping jack and an anchor pile attached to the excavation rod via a chuck device is set on the pile drive tower, and the excavator is driven into the steel pipe pile. Excavate the bedrock following the sedimentary layer by enlarging the diameter of the diameter expansion bit to make the excavation diameter larger than the diameter of the anchor pile, then stop the excavation at the required depth and reduce the diameter of the diameter expansion bit to set the expansion jack. As it contracts, the excavator is pushed forward to push the anchor pile to the bottom of the borehole, and this process of excavating the diameter expansion bit and pushing the anchor pile is repeated.
When the anchor pile reaches a predetermined depth in the bedrock, the anchor pile is separated from the chuck device, the excavator is removed, and the mortar is injected into the steel pipe pile using a mortar injection pipe between the anchor pile, the bedrock, and the steel pipe pile, between the anchor pile and the steel pipe. A diagonal pile driving method characterized by filling the inside of the pile and integrating the steel pipe pile and the bedrock via an anchor pile.