JPH035589A - Boring device - Google Patents

Abstract

PURPOSE:To facilitate the confirmation of depth bored by providing a bucket protruding outside the rotational locus of boring claws and storing the earth bored after boring the vicinity of underground hole. CONSTITUTION:While bentonite is discharged from a claw part 9 through the cylinder shaft 6 of rotation shaft and boring claw part 9, the rotation shaft is rotated normally to bore an underground hole. The rotation shaft is then rotated reversely to position a diameter widening claw 11 and a bucket 12 in a rotation locus Q, and the rotation shaft 3 and a boring device A are pulled out from the hole. The earth bored and stored in the bucket 12 is observed to confirm that the tip end of claw part 9 has reached a specified depth of support layer. When it is confirmed, the rotation shaft is lowered to resume the claw part 9 to the bottom of hole, and the rotation shaft is rotated reversely to drive the claw 11 and bucket for a wide diameter boring. After the claw 11 and 12 are reduced in their diameters, the device A is pulled out while cement mortar is discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improved technology for excavation equipment used for construction of underground piles, column-type retaining walls, etc. constructed by the pre-poling method.

[Conventional technology]

One of the pre-poling methods for constructing, for example, underground piles using ready-made piles is the so-called RODEX construction method for constructing expanded-bottom piles as follows.

This construction method first involves boring multiple locations on the construction site to create a soil log map, and then estimates the distribution of strata throughout the construction site based on this soil log map. A test excavation is carried out at the location, and the change in the excavation load at that time is read by the resistance value in ammeter, and the resistance value corresponding to the support layer of the above-mentioned estimated stratum is confirmed.

Then, an excavating device equipped with a digging claw is connected to the tip of a rotating shaft that can be driven in forward and reverse directions to which a supply pipe for a fluid such as bentonite is connected, and the excavating device rotates while discharging bentonite etc. from the tip of the excavating device. The shaft is driven in normal rotation, the digging claw forms an underground hole reaching a predetermined depth of the support layer based on the estimation, and the excavation load at that time is read in ammeter, and the tip of the digging claw of the drilling device is It is electrically confirmed that the depth has reached the estimated predetermined depth of the support layer.

Next, while pulling up the rotating shaft slightly, the rotating shaft is reversely driven to enlarge the diameter-expanding claw attached to the vicinity of the excavating claw of the excavating device to expand the diameter of the area around the bottom of the underground hole, and then, The rotary shaft is driven to rotate in the normal direction to reduce the diameter of the diameter-expanding claw, and the rotary shaft is lowered to return the claw tip to the enlarged-diameter bottom side, and a predetermined amount of cement mortar is applied from the claw tip to the diameter-expanded bottom. Pull out the digging claw from the underground hole while discharging it,
An existing concrete shaft is buried or cast into the underground hole with its lower end inserted into the cement mortar.

According to this construction method, in addition to confirming the depth of the bearing layer based on the soil profile diagram, the tip of the pile is electrically confirmed from changes in excavation load to ensure that the tip of the pile has reached the specified depth of the bearing layer. However, it was assumed that it was possible to construct expanded piles that reached a specified depth in the bearing layer.

[Problem to be solved by the invention]

However, the distribution of strata according to the soil log map is based on speculation, and there is no problem if there is little change in the depth of the supporting layer, but if the supporting layer changes locally. Sometimes, based on the above estimation, an underground hole that reaches the specified depth of the supporting layer may not be excavated, and in order to avoid such a situation, the resistance value of the ammeter is read and the nail tip is supported. This method is used to check whether the specified depth of the layer has been reached, but since the excavation load is greatly affected by the digging speed of the drilling equipment, it lacks accuracy. There was a problem with the inability to respond to changes.

Furthermore, when constructing a pillar-type retaining wall, it goes without saying that it is a prerequisite to excavate an underground hole where the tip of the nail reaches the impermeable layer; It is not possible to confirm whether or not the predetermined depth of the impermeable layer has been reached, and it is difficult to accurately determine whether the underground hole drilled based on the above estimation has reached the desired predetermined depth of the stratum using TI.
M? We are looking forward to the provision of a means to do this.

The present invention was devised to meet these demands, and is an excavator that can accurately confirm whether the tip of the claw has reached a predetermined depth in the desired stratum through simple improved technology. is intended to provide.

(Means for Solving the T! Problem) The excavating device according to the present invention, which has achieved the above-mentioned object, is capable of driving a rotary shaft in the vicinity of the excavating claw that forms an underground hole by driving the rotating shaft in the forward and reverse directions. , is characterized in that a bucket is provided which protrudes out of the rotation locus of the excavating claw when viewed in the direction of the rotational axis of the rotational shaft as the rotational shaft is reversely driven, and which excavates around the underground hole and accommodates the excavated soil.

[Effect]

According to the above characteristic structure, the rotary shaft is driven in reverse at the time when the tip of the excavating claw of the excavating device is estimated to have reached a predetermined depth of the desired stratum based on the soil profile, excavation load, etc. When the bucket is projected out of the rotation locus of the excavating claw, the area around the bottom of the pond hole is excavated by the bucket, and the excavated soil is stored in the bucket.

Here, the rotary shaft is driven in normal rotation to reduce the diameter of the bucket within the rotation locus of the excavation claw, and the excavation device is pulled out from the underground hole along with the rotary shaft to remove the excavated soil contained in the bucket. By observing, it is possible to visually check the soil quality of the stratum around the bottom of the underground hole, and by extension, it is possible to accurately confirm whether the tip of the nail has reached the desired predetermined depth of the stratum. be able to.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

1 and 2 show an excavating rig A, and FIG. 3 shows an example of an excavating machine B equipped with the above-mentioned excavating rig A, and the excavating machine B is a crawler type Traveling trolley l
A post 2 is erected on the front side of the post 2, and the post 2 is provided with an elevating means 4 for driving up and down a rotating shaft 3 of a hollow structure that is successively added and connected, and a rotating shaft connected to the elevating means 4. A forward/reverse drive means 5 for driving the excavator A in the forward and reverse directions is provided at the lower side of the post 2, and a cylindrical shaft 6 of the excavating device A is connected to the lower end of the rotary shaft 3.

The excavating device A has two excavating claws 9 each having a plurality of claw bodies 8 provided on the lower edge of a wing plate 7, and which are provided on the lower outer periphery of the cylinder shaft 6 with a phase of 180 degrees to each other. , each digging claw 9
A bracket 10 integrally connected with a stopper a is provided on the cylindrical shaft 6 in the upper part of the cylinder, and one of the brackets 10 is provided with a diameter expanding claw 11, and the other bracket 10 is provided with a bucket 12, respectively. It is pivotally connected via a pin 13 parallel to the axis of the shaft 6.

When the excavating claw 9 excavates an underground hole under normal rotation of the rotating shaft 3, each of the diameter expanding claw 11 and the bucket 12 is rotated toward the cylindrical shaft 6 side, and the digging claw 9 is rotated in the normal direction. In the rotational trajectory Q of the excavating claw 9 when viewed in the direction of the rotational axis (
(see FIG. 2), and the rotating shaft 3
4 to 6, most of the enlarged diameter claws 11 and the bucket 12 protrude outside the rotational trajectory QQ of the excavation claws 90, as shown in FIGS. 4 to 6. It is configured to expand the diameter of the bottom of the underground hole excavated by the excavated soil, and to store the excavated soil in the bucket 12.

Next, to explain one procedure for constructing an expanded bottom pile using the RODEX method, first, as shown in FIG.
is connected, and the rotating shaft 3 is driven in normal rotation while discharging bentonite etc. from the tip of the claw through the rotating shaft 3 and the cylindrical shaft 6 of the digging claw 9. Then, the underground hole is excavated when the tip of the excavating claw 9 of the excavating device A is estimated to have reached the desired predetermined depth of the support layer C. In addition, in this example, the support layer C
It is assumed that the nail tip has not reached a desired predetermined depth of the support layer C due to a local change in the nail tip.

Here, the rotary shaft 3 is driven in the reverse direction, and as shown in FIG. The bucket 12 is used to excavate the area around the bottom of the underground hole of the estimated predetermined depth (as shown in phantom lines in FIG. 1), and the excavated soil is stored in the bucket 12.

Next, the rotary shaft 3 is driven in reverse to position the diameter-expanding claw 11 and the bucket 12 within the rotation locus Q, and the excavation device A is pulled out of the underground hole together with the rotary shaft 3, and the bucket Based on the excavated soil contained in 12, the soil quality of the support layer C around the bottom of the underground hole of the estimated predetermined depth is visually observed, and this allows the nail tip to reach the desired predetermined depth. It is confirmed that the support layer C has not been reached.

However, in this embodiment, the tip of the nail has the desired support layer C.
This is because it shows an example in which the tip of the nail has not reached the specified depth of the desired support layer C, and if the tip of the nail has reached the specified depth of the desired support layer C, the excavated soil stored in the bucket) 12 is Then, it is visually confirmed that the tip of the nail has reached the desired predetermined depth of the support layer C.

Based on the confirmation that the nail tip has not reached the desired predetermined depth of the support layer C, until it is confirmed that the nail tip has reached the desired predetermined depth of the support layer C, The above-mentioned underground hole is excavated, the excavated soil around the underground bottom is stored in the bucket 12, and the soil quality of the stored excavated soil is observed.

When it is confirmed that the tip of the claw has reached the desired predetermined depth of the support layer C, the rotary shaft 3 is lowered to return the digging claw 9 of the excavation device A to the bottom of the pond hole. While pulling up the rotating shaft 3 slightly, the rotating shaft 3 is driven in reverse, and the diameter-expanding claw 11 and the bucket 12 are used to expand the diameter of the bottom of the underground hole (see Fig. 5). The rotary shaft 3 is driven in normal rotation to reduce the diameter of the diameter-expanding claw 11 and the bucket 12 within the rotation trajectory Q, and the rotary shaft 3 is lowered to bring the tip of the excavating claw of the excavating device A toward the diameter-expanded bottom side. Then, as shown in FIG. 7, a predetermined amount of cement mortar 15 is discharged from the tip of the claw to the bottom of the enlarged diameter in place of the bentonite, etc., and the drilling device A is pulled out of the underground hole, as shown in FIG. , the cement mortar 1
By burying or driving a pre-formed concrete shaft 16 into the underground hole with its lower end protruding into the hole 5, an expanded bottom pile 17 whose tip reaches a predetermined depth of the support NC is constructed.

The bucket 12 has a rectangular recess 12a for storing excavated soil formed in the bucket main body 12b as shown in FIG. 4, but it may also have a shape as shown in FIGS. Deformation is possible.

That is, what is shown in FIG. 9 is a recess 12a for storing excavated soil.
The recess 12a is shaped so that the excavated soil stored in the recess 12a does not overflow.

What is shown in FIG. 10 is a bucket body 12b in which a recess 12c for storing excavated soil is formed in the shape of a recess without a wall on the back side. While excavating the surrounding area, any fluids that have entered the excavated soil storage section 12c up to that point are removed by the excavated soil, and the excavated soil is placed in the excavated soil storage recess 12c in the shape of the inner part. It is unique in that it is accommodated by biting into it.

In this embodiment, the construction of the expanded-bottom piles 17 has been described, but it goes without saying that the construction of piles for column-type retaining wall work can also be implemented.

〔Effect of the invention〕

As explained above, the excavation device according to the present invention is characterized in that it excavates around an underground hole by driving the rotary shaft in reverse, and that a bucket for storing the excavated soil is provided near the excavation claw. Then, when it is estimated that the tip of the excavating claw reaches a predetermined depth in the desired stratum based on the soil profile, excavation load, etc., the rotary shaft is driven in the reverse direction, and together with the rotary shaft, the By pulling the bucket out of the underground hole and observing the excavated soil contained in the bucket,
It is now possible to visually check the soil quality of the stratum around the bottom of the underground hole, that is, it is possible to accurately check whether the tip of the nail has reached the desired depth of the stratum, and By using a drilling rig with this structure,
It has now become possible to construct a pile that can be recognized when the tip of the pile has reached a predetermined depth in the desired stratum.

[Brief explanation of the drawing]

FIG. 1 is a side view of the excavating device, FIG. 2 is a longitudinal sectional plan view of the excavating device, and FIG. 3 is a side view of the excavating machine. FIG. 4 is a perspective view of the bucket, FIG. 5 is a side view of the excavation device showing the state of excavation around the underground hole by expanding the diameter of the diameter-expanding claw and the bucket, and FIG. 6 is a longitudinal sectional plan view thereof. FIG. 7 is an explanatory diagram of a state in which the excavator is pulled out of an underground hole while discharging cement mortar, and FIG. 8 is a side view of the expanded bottom pile with the tip of the pile reaching the support layer. FIG. 9 and FIG. 10 are perspective views with main parts of the bucket of the embodiments cut away, respectively. 3...Rotation axis, 9...Drilling claw, 12...Bucket, Q...Rotation locus. Figure 7 Figure 8

Claims (1)

[Claims] In the vicinity of an excavating claw that forms an underground hole by forward rotation of a rotary shaft that can be freely driven in forward and reverse directions, as the rotary shaft is driven in the reverse direction, the rotary shaft protrudes out of the rotation trajectory of the excavating claw when viewed in the direction of the rotation axis of the rotary shaft, and An excavation device characterized by being equipped with a bucket for excavating around an underground hole and storing excavated soil.