JP4667009B2 - How to bury underground anchors - Google Patents

Description

The present invention provides an underground anchor for supporting a branch line for supporting a columnar object such as a power pole such as a distribution line and a telephone line, a pole of a traffic signal, or a predetermined structure such as a building structure in the ground. Relates to the method of burying .

Some applicants among the present applicants (the same applies to the following applicants) are first columnar objects such as utility poles and structures such as buildings (hereinafter, “electric poles” will be described as an example). An underground anchor for supporting a branch line supporting the ground in the ground is proposed (see Patent Documents 1 to 4). Underground Ann mosquitoes according to the proposal is described in detail in the section of the embodiment of the present invention, be configured to only intermittently plurality set a helical drilling blade on the distal end side of the shaft portion of the rod-like The shaft portion opposite to the tip side is configured to be attached to a rotating portion of a digging pillar car used when standing a power pole on the ground, a so-called auger tip via a predetermined construction tool. . Therefore, since the underground anchor according to this proposal enters so as to excavate the underground when the auger of the drilling column car is rotated, the underground anchor can be easily buried deep in the ground. . Then, its buried underground anchors in the ground, the branch line made of steel wire which supports the utility pole is Ru attached to branch bars provided in the ground anchor.

By the way, the power pole cannot be supported unless the force for supporting the branch line of the underground anchor, that is, the tensile strength of the underground anchor, is not less than a predetermined value. In other words, if the underground anchor buried in the ground is pulled out from the ground below a predetermined force required to support the utility pole, it cannot function as an underground anchor. For example, when the force required for the branch line supporting the utility pole is 98 kN (10 ton), when the underground anchor is pulled out when a pulling force of 98 kN is applied to the branch line, it will serve as the underground anchor. I can't. The tensile strength of the underground anchor, which is the force against this pulling force, is caused by the resistance force of the excavating blades provided on the shaft portion constituting the underground anchor to the ground, and the resistance force is the resistance of the underground anchor. It has a property that depends greatly on the soil to be buried.

Therefore, the present applicant has proposed a measuring tool that can appropriately select an underground anchor that matches the soil quality of the underground anchor burial site (see Patent Documents 5 and 6). This measuring tool has a simple configuration in the form of a rod, and is attached to the tip of an auger of a digging pillar car. .5Cm, obtained from the resistance of the ground generated when implanted hollow measuring instrument of length 81.0cm (the sampler) into the ground, 75 cm hammer mass 63.5 kg (about 622.3N) to the above-described measuring instrument It is obtained from the number N of hits required to drop the tool freely from the height of 30 mm and drive the measuring tool 30 cm.). This measurement tool can be used to determine the N value at the point where the underground anchor is buried, that is, the soil quality at the underground anchor's buried point can be determined. Select an underground anchor with a drilling blade of a size suitable for the soil quality. Can be buried. When the underground anchor is appropriately selected, the underground anchor can have a tensile strength higher than a predetermined value.
JP 2000-1850 A JP 2001-59221 A JP 2001-182058 A JP 2001-271345 A JP 2003-227126 A JP 2003-239282 A

However, when burying the underground anchor according to the above proposal, the type of the underground anchor to be used is selected by measuring the N value of the underground anchor, and the underground anchor has a predetermined tensile strength. Therefore, the underground anchoring work required a soil survey process. Therefore, it has been desired to be able to estimate the tensile strength of the underground anchor without requiring such a soil investigation process.

Therefore, the present invention has been made to meet the above-mentioned demand, and its purpose is to embed an underground anchor without the need to measure the N value of the underground anchor burying point . An object of the present invention is to provide an underground anchor burying method capable of estimating the tensile strength of an underground anchor at a depth .

The present invention, in order to achieve the above object, buried method of underground anchor to support branch supporting the pillars and buildings like structures such as utility poles have a helical drilling blade tip side in the ground in the ground anchor is rotated by the hydraulic motor is embedded to a predetermined depth, as well as measured using the measuring means driving hydraulic pressure of said hydraulic motor when embedded to a predetermined depth, based on the measurement value, Estimating the tensile strength of the underground anchor that is the force that supports the branch line in the ground, and if the tensile strength value is equal to or greater than a predetermined value, the underground anchor is left in the ground, and the tensile strength is set to the predetermined value. when not reached, it is characterized in Succoth Eject the ground anchor from the ground.

According to the present invention, the ground anchor is rotated by the hydraulic motor is embedded to a predetermined depth, the driving hydraulic pressure of said hydraulic motor when embedded to a predetermined depth, as well as measured using the measuring means, since estimates the tension force of the ground anchor is a force for supporting the branch in the ground based on the measurement value, it is possible to omit the soil survey, such events preceding N values measured, the ground anchor burying operation it is possible to save Chikaraka. If the tensile strength value is equal to or greater than the predetermined value, the buried underground anchor remains in the ground, and when the tensile strength does not reach the predetermined value, the underground anchor is taken out from the ground by the hydraulic motor. The middle anchor can be securely embedded with the required tensile strength .

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 shows a hydraulic system for carrying out a method for estimating the tensile strength of an underground anchor according to an embodiment of the present invention. This hydraulic system is actually a drilling column in FIG. Provided in the car.

In FIG. 1, P is a hydraulic pump that sucks and pressurizes the oil O in the oil reservoir V through the suction pipe P0. Pressurized for oil in the hydraulic pump P, both when the auger or the like, which will be described later, via a supply pipe P1 Ru is supplied to the hydraulic motor M for rotating, for oil discharged from the hydraulic motor M, return pipe P2 It is comprised so that it may return to the oil sump V via. A meter G corresponding to the measuring means of the present invention for measuring the hydraulic pressure in the supply pipe P1, that is, the drive hydraulic pressure of the hydraulic motor M, is provided in the supply pipe P1.

The instrument G is provided in the cab of Anaho Kenbashira vehicles or civil engineering machinery, made from a pressure gauge of known analog, the scale plate g0 of the instrument body, a circle indicating the tension force in the ground anchor An arc-shaped tension-proof graduation g1 and an arc-shaped hydraulic graduation g2 indicating the drive hydraulic pressure of the hydraulic motor M are provided in such a manner that the arc centers coincide with each other, and both the graduations g1 and g2 are simultaneously indicated by the needle g '. It is configured as follows. For these relationships both scale g1, g2 will be described later.

The instrument G is an analog type here, but it can also be a digital type using a known analog-digital conversion circuit and numerical display circuit. When the instrument G is digital, the tensile strength of the underground anchor and the drive hydraulic pressure of the hydraulic motor M can be specifically recognized by numerical values. In the above-described example, the instrument G is provided with the hydraulic scale g2 in addition to the tensile strength scale g1, but it may be provided with only the tensile strength scale g1. But as mentioned above,
In addition to when the oil pressure scale g2 also provided a tension force scale g1, it is convenient because the driving hydraulic pressure of the hydraulic motor M can be known <br/> Rukoto.

The relationship between the tension scale g1 and the hydraulic scale g2 provided on the scale plate g0 of the instrument G is determined from the data obtained based on the applicant's many years of experience in the underground anchor and many past results. ing. That is, the applicant of the present invention has a certain proportionality between the drive hydraulic pressure of the hydraulic motor M when the underground anchor is embedded at a predetermined depth and the tensile strength of the underground anchor embedded at the predetermined depth. It was Heading that there is a relationship. As a result, as in the prior art, the tensile strength can be estimated from the hydraulic pressure when the underground anchor is buried without measuring the N value of the underground anchor in advance. The proportional relationship between the hydraulic pressure of the hydraulic motor M and the tensile strength of the underground anchor varies depending on the soil , the shape (type) and size of the anchor. Change the tension scale g1. FIG. 2 shows an example of this proportional relationship.

In FIG. 2, the vertical axis represents the maximum tensile strength (kN) of the underground anchor , and the horizontal axis represents the hydraulic pressure (MPa) when the underground anchor is stopped. The ground used for this experiment is the Dotan ground, the filled mark in FIG. 2 is the cut ground, and the white mark is the embankment. Moreover, 90 cm, 110 cm, and 135 cm in FIG. 2 represent the embedding depth of the below-mentioned 140 φ underground anchor. In FIG. 2, a line indicating a thick proportional relationship is obtained by the least square method (see the formula in FIG. 2), and σ = 10.4 represents a standard deviation.

Hereinafter, the underground anchor embedding method will be described more specifically. The underground anchor used here is called a standard type, and the diameter of the uppermost spiral excavating blade (see 2d in FIG. 3 to be described later) is 140 mm (hereinafter referred to as 140φ). The length of the shaft rod (see 1 in FIG. 3 described later) is 450 mm, and the diameter of the thickest portion of the shaft rod (the portion of the largest-sized spiral excavating blade) is 50φ. Hereinafter, this underground anchor will be described as an underground anchor of 140φ.

  As shown in FIG. 2, when the underground anchor of 140φ is buried to a predetermined depth from the ground in the earthen ground using a digging column car, that is, a branch bar connected to the upper part of the underground anchor (described later) (See 7 in FIG. 3) When the underground anchor is buried so that the upper end of the upper end of the ground is at a predetermined height from the ground (usually from the ground at this time to the tip of the underground anchor (see 3 in FIG. 3 described later)) It was confirmed that if the driving pressure of the hydraulic motor that rotates the auger of the auger is 13.1 MPa or more, the necessary tensile strength of the underground anchor can be secured at 63.7 kN or more ( (See chain line in FIG. 2).

Figure 3 is a shows the burying method of underground anchor according to the present invention. First, the underground anchor A will be described. The ground anchor A is made of cast iron, has a shaft rod 1 having a predetermined length, the distal end side of the shaft rod 1 (Figure 3, lower end), several double (in the illustrated example 4 ) Helical excavation blades 2a to 2d are provided intermittently . These spiral excavation blades 2a to 2d are configured such that the diameter of the spiral excavation blades 2a to 2d increases, that is, 2b is larger than the spiral excavation blade 2a, and 2c is larger than 2b. The sides and outer circumferences of these spiral excavating blades 2a to 2d entering the ground are sharply formed. Moreover, the front-end | tip part of the axial rod 1 is formed in the drill part 3 which has the same cutting blade as a well-known drill.

On the upper end side opposite to the drill portion 3 of the shaft rod 1, that is, on the ground side when the underground anchor A is buried in the ground, a collar portion 4 having a diameter slightly larger than the diameter of the shaft rod 1 is provided. And the upper end portion of the collar portion 4 is formed in a rectangular column portion 5 having a quadrangular cross section . And this prismatic part 5 is provided with the hole 5a, and it is comprised so that the branch bar mentioned later may be attached.

In FIG. 3, 6 is a construction tool, and this construction tool 6 is composed of one cylindrical body that can accommodate the branch bar 7 therein, and at one end thereof (the lower end side in FIG. 3) , together with the square hole 6a of the prism portion 5 of ground anchor a is removably fitted is formed, the other end (in FIG. 3 upper side), hole drilling Kenhashirasha (not shown) prismatic mounting portion 6b which is inserted into prismatic insertion port 10a provided in the auger 10 is formed. And inside this construction tool 6, the space 6c which has sufficient volume to accommodate the branch bar 7 opened to the square hole 6a is formed. The branch bar 7 is configured to be attached to a hole 5a provided in the prism 5 of the underground anchor A, and is rotatably connected to the hole 5a via a ring 7a provided in the lower part. It is configured.

In FIG. 3, reference numeral 6 d denotes a through hole, which is provided penetrating on the upper side of the construction tool 6. Therefore, when the branch bar 7 is inserted into the construction tool 6, the bolt 6e is passed through the ring 7b and the through hole 6d of the branch bar 7, and a nut (not shown) is screwed into the bolt 6e. rod 7 is connected to the installation tool 6.

To buried underground anchor A in the earth using a construction tool 6, first, the mounting portion 6b of the installation tool 6 is inserted into the insertion opening 10a of the auger 10. And in order to prevent dropout, the bolt 10c is penetrated by the through-hole 10b provided in the front-end | tip of the auger 10, and the through-hole 6f provided in the mounting part 6b, and is fixed with the nut 10d.

Next, the branch rod 7 is inserted into the construction tool 6, and the prism 5 of the underground anchor A is fitted into the square hole 6a. Then, the bolts 6e is penetrated into the through-hole 6d provided in the construction tool 6, the bolts 6e nut (not shown) is screwed, thereby connecting the a branch rod 7 and construction tool 6 Kept in a state.

When the auger 10 rotates the hydraulic motor M while maintaining the pressing state, the ground anchor A, the spiral embedded in Mel started in the ground by the action of the digging edge 2 a to 2 d. Then, when the lower part of the underground anchor A is buried at a predetermined depth, the bolt 6e is extracted. When the underground anchor A is buried at a predetermined depth, that is, when the upper end side of the branch bar 7 reaches a predetermined height from the ground, it is resistant to the instrument G installed on the cab of the digging pillar car. The tension is read. If the value of this read was tension force greater than a predetermined value, the rotation is stopped auger 10 of the hydraulic motor M is Ru is moved upward. As a result, the construction tool 6 is detached from the underground anchor A, and the underground anchor A and the lower ends of the branch rods 7 are kept buried in the ground. Thereafter, a wire (not shown) is attached to the ring portion 7b provided on the upper portion of the branch bar 7 to support the utility pole. When the tensile strength read from the instrument G does not reach a predetermined value, the buried underground anchor A means that the predetermined tensile strength for supporting the utility pole cannot be obtained. in this case, Ru is rotated in the rotational direction opposite to the direction of the hydraulic motor M is far (reverse rotation). By this reverse rotation, the underground anchor A is gradually brought out to the ground surface and taken out from the ground.

  In the above-described example, the tension resistance is displayed in an analog or digital manner using a meter. However, a voice, a buzzer, or a display lamp is used together with the meter display or in place of the meter display. You may make it perform. When displaying the tensile strength with voice, specific numerical values are voice-guided, and when displaying the tensile strength with a buzzer, the tone when the predetermined tensile strength is met, and when the predetermined tensile strength is not met When the tone strength is displayed on the indicator lamp, the display color when the specified tension is satisfied and the display color when the specified tension is not satisfied are notified. Is done.

It is a schematic block diagram of the hydraulic system for enforcing the tension | tensile_strength estimation method of the underground anchor which concerns on one embodiment of this invention. It is a graph which shows the relationship between the oil_pressure | hydraulic of a hydraulic motor, and the tensile strength of an underground anchor. It is explanatory drawing when a hydraulic motor is provided in the hole excavation pillar car.

P Hydraulic pump M Hydraulic motor G Instrument (measuring means)
g 'Needle g1 Tensile Strength Scale g2 Hydraulic Scale A Underground Anchor 6 Construction Tool 7 Branch Bar 10 Auger

Claims (1)

A buried method ground anchors to support branch supporting the pillars and buildings like structures such as utility poles have a helical drilling blade distally in the ground,
It said ground anchor is rotated by the hydraulic motor is embedded to a predetermined depth,
With measured using the measurement means driving hydraulic pressure of said hydraulic motor when embedded to a predetermined depth, to estimate the tension force of the ground anchor is a force for supporting the branch in the ground based on the measurement value,
Leaving the value of the tension force is the ground anchor equal to or greater than a predetermined value in the ground, when the tension force does not reach the predetermined value, and wherein Succoth Eject the ground anchor from the ground How to bury underground anchors.

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