JP2000230234A - Pipe earth measuring method in construction of open end steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the working property of measurement by providing an optical wave range finder on a clamp attachably and detachably mounted within a steel pipe pile, and measuring the height of the pipe earth at the time of penetrating the pipe into the ground. SOLUTION: A clamp 3 attachably and detachably mounted within an open end steel pipe pile 1 has an optical wave range finder 4 to measure the height (h) of the pipe earth 2 intruding into the pile 1 in no contact. The position of the range finder 4 is set within a limit distance related to the clamp set error and the beam characteristic so that an optical wave beam 5 never interferes with the inner wall of the pile 1. When an open end steel pipe pile having a blade on the lower end outer surface thereof is rotated and pressed into the ground, the range finder 4 is provided on the pile in the same manner, and the pipe earth height measurement data is radio transmitted from a transmitter provided at the top of the pile to a receiver on the ground to measure the height of the pipe earth intruding into the pipe in no contact in the penetration of the pile to the ground. According to this, the measurement can be safely performed without interrupting the penetrating work of the pile, and the tip support force of the pile can be precisely evaluated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the height of soil which penetrates a steel pipe pile having an open lower end when penetrating the pipe.

[0002]

2. Description of the Related Art The pushing support force of a steel pipe pile used as a foundation pile of a building or civil engineering structure is the sum of the peripheral friction force and the tip resistance. Among them, in the calculation of the tip resistance, in the case of an open-ended steel pipe pile whose tip is released, the tip resistance due to the blockage of the tip of the steel pipe pile due to the earth and sand that has penetrated into the pipe at the time of intrusion by driving or press fitting can be evaluated. However, it is known that this blocking action tends to make it difficult for the soil inside the pipe to penetrate from the tip when the diameter of the steel pipe pile increases, and that the blocking action tends to be difficult to obtain. It is necessary to know the blockage rate. Since this closing effect is closely related to the height of the soil in the pipe, the closing rate can be estimated by measuring the height of the soil in the pipe (the distance from the tip of the steel pipe pile to the surface of the soil that has entered the pipe).

[0003] The closing rate serves as an index for evaluating the tip resistance of the steel pipe pile. In other words, as the steel pipe pile with the open lower end penetrates into the ground, soil penetrates into the pipe,
The height of the soil inside the pipe increases, but at a certain height, the effect of closing the tip can be expected due to the friction force between the inner peripheral wall of the steel pipe pile and the soil, so the tip resistance of the closed cross-sectional area is evaluated in the bearing capacity calculation be able to. For example, if there is no pipe soil at all, the tip resistance can be evaluated only by the thickness of the steel pipe pile, but if there is sufficient pipe soil height, the steel pipe pile tip will be closed due to frictional resistance of the pipe inner peripheral surface. The entire area of the tip can be evaluated as the tip resistance.

[0004] The measurement of the soil height in the pipe is an important parameter in the construction of the steel pipe pile by the rotary press-in method, in addition to the penetration construction of the steel pipe pile by driving or press-fitting.

In the rotary press-in method, a steel pipe pile having blades provided on the outer surface at the lower end can be rotatably pressed into the steel pipe pile without noise and without vibration, and can easily be penetrated. It can demonstrate support. In addition, since this construction method has the feature that the bearing capacity can be evaluated from the measured data during construction such as torque during press-fitting, press-fitting, etc., highly reliable construction management while confirming the supporting force for each steel pipe pile Can be. In this bearing capacity evaluation, if the height of the soil inside the pipe during the construction of the steel pipe pile can be measured continuously, the bearing capacity is calculated in real time by combining this data with the construction management data such as torque and press-in. It becomes possible.

Conventionally, the method of measuring the soil in a pipe, which has been performed in the hitting method or the press-fitting method of a steel pipe pile, is as shown in FIG. 8, in which a measuring rope 12 with a weight 11 is inserted from the top of the steel pipe pile 1 into the pipe. There is a simple method of measuring the distance L1 between the surface 2a of the pipe soil 2 and the top of the steel pipe pile 1 by suspending the pipe and subtracting it from the total length L of the steel pipe pile to obtain the pipe soil height h.

[0007]

However, according to the above-mentioned conventional method, it is necessary to interrupt the construction of the steel pipe pile at the time of measurement, and when the top of the steel pipe pile is higher than the ground, the work becomes dangerous at a high place. Because of this, it was usually performed after the completion of placing and press-fitting of steel pipe piles. For this reason, there was a problem that continuous data of the soil in the pipe during construction could not be obtained. An object of the present invention is to solve this problem and to make it possible to continuously measure the height of soil in a pipe safely and in real time during the intrusion of a steel pipe pile.

[0008]

In order to achieve the above object, the present invention has the following configuration. The invention according to claim 1 provides a method for measuring the height of soil 2 in an open-ended steel pipe pile 1 having an open end, wherein a lightwave distance meter 4 attached to a detachable clamp 3 is provided in the steel pipe pile 1. This is a method for measuring soil in a pipe at the time of constructing an open-ended steel pipe pile, characterized in that the height h of soil that penetrates into the pipe when the pile 1 penetrates into the ground is measured in a non-contact manner.

According to a second aspect of the present invention, the setting position of the lightwave distance meter 4 attached to the detachable clamp 3 in the first aspect is adjusted so that the lightwave beam 5 does not interfere with the inner wall of the steel pipe pile 1. This is a method for measuring the soil height in a pipe within the limit distance A related to the beam characteristics.

Further, the invention according to claim 3 is a rotary press-fitting pile method in which an open-end steel pipe pile 1 provided with blades 8 on the outer side surface at the lower end of the steel pipe pile is rotationally press-fitted and buried, and is detachable from the steel pipe pile 1. A lightwave distance meter 4 attached to a simple clamp 3 is provided, and a transmitter 9 provided at the top of a steel pipe pile transmits the height measurement data inside the pipe to a receiver 10 on the ground, and the steel pipe pile 1 penetrates into the ground. This is a method for measuring soil in a pipe at the time of construction of an open-ended steel pipe pile, wherein the height h of soil invading the pipe is measured without contact.

[0011]

According to the soil height measuring method of the present invention, when the steel pipe pile 1 penetrates into the ground, the lightwave distance meter 4 is fixed to the clamp 3 which is detachably provided above the open-ended steel pipe pile 1. attachment,
The light wave beam 5 oscillated from the light wave distance meter 4 continuously measures the distance L2 to the surface 2a of the soil in the pipe in a non-contact manner. Although various types of laser rangefinders can be used as the lightwave rangefinder 4 to be used, it is desirable to use a semiconductor laser rangefinder that can use a compact oscillator because it is set in a narrow space inside a steel pipe pile.

The lightwave distance meter 4 is set on the inner wall of the steel pipe pile 1 by the clamp 3.
As several pipes having a length of 0 m penetrate into the ground and are welded and extended, the clamp 3 needs to be detachable so that the setting can be easily changed when the steel pipe pile 1 is joined. .

The clamp 3 employs a mechanism for pressing and holding the inner wall of the steel pipe pile 1 and is desirably detachable from the ground by remote control.

The lightwave distance meter 4 set in the steel pipe pile 1 is
If the distance from the soil surface 2a in the pipe is too large, the influence of the pipe wall becomes a problem in a narrow steel pipe. One of the reasons is a problem of inclination accuracy when setting the optical distance meter 4 with the clamp 3. That is, the lightwave distance meter 4 is inclined and the steel pipe pile 1
2A, if the distance from the inner surface 2a of the pipe is long, a slight inclination s is greatly shifted due to the action of the optical lever, as shown in FIG. It deviates from the surface 2a and hits the tube wall, and is refracted and reflected, causing a measurement error or making measurement impossible. Further, when a semiconductor laser is used, the device can be made compact, but the degree of condensing of the laser beam 5 is low. Therefore, when the oscillation distance becomes long, the diffused light wave beam 5 interferes with the tube wall as shown in FIG. Would. Also in this case, the light wave beam 5 hitting the tube wall is refracted and reflected, which causes a measurement error or measurement failure.

The invention according to claim 2 solves this problem. In order to prevent the light wave beam 5 from interfering with the tube wall, the light wave distance meter 4 is set within a limit distance A related to the clamp set error and the beam characteristics. It is intended to be set. Here, the limit distance A is calculated by adding the deviation (r2) of the optical axis of the light beam 5 due to the clamp set tilt error to the light beam radius (r
The distance obtained by adding 1) is the same as the radius (r) of the steel pipe pile 1. That is, as shown in FIG.
When the inclination error at the time of clamp set is (s degrees),
A where A × (tans) + (r1) = r is defined as the limit distance.

A third aspect of the present invention is a method for rotationally press-fitting a steel pipe pile 1 in which the height of soil 2 in a pipe is non-contactly measured by an optical distance meter 4. When the rotary press-fitting method is used as the means for penetrating the steel pipe pile 1, the signal transmission of the optical distance meter 4 cannot be performed by wire since the steel pipe pile 1 rotates at the time of measurement. For this reason, the data of the soil height in the pipe measured by the lightwave distance meter 4 is wirelessly transmitted from the transmitter 9 provided on the top of the steel pipe pile 1 to the receiver on the ground, and is measured.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention. The steel pipe pile 1 to which the present invention is applied mainly has a diameter of 50 mm.
This is an open-ended steel pipe pile having a large diameter of 0 mm or more and an open end. Penetration into the ground is performed by a hammering method using a hammer, a press-fitting method, or a rotary press-fitting method.

When the open-ended steel pipe pile penetrates into the ground, soil penetrates into the penetration from the pile tip, and when the height of the soil 2 in the pipe increases, the pile tip has a function of closing the pile tip. The present invention provides a method of measuring the height of soil 2 in a steel pipe pile 1 in a non-contact and continuous manner with a lightwave distance meter 4. The measuring means sets a lightwave distance meter 4 attached to a detachable clamp 3 at a predetermined position in the steel pipe pile 1, oscillates a lightwave beam 5 toward the tip of the steel pipe pile, and generates a light beam at the surface 2 a of the soil 2 in the pipe. The reflected light wave beam 5 is captured, the signal is processed by the measuring device 4a to measure the distance L2, and the arithmetic processing is performed to find the soil height h in the pipe.

The lightwave distance meter 4 uses a semiconductor laser beam distance meter so that a small oscillator can be used.
And set it at a predetermined position on the steel pipe pile 1.

The clamp 3 to which the lightwave distance meter 4 is attached
As shown in FIG. 4, the inner wall of the steel pipe pile is pressed and detachably held by the telescopic cylinder 3a, and the telescopic cylinder 3a may be of a pneumatic, hydraulic, electric or manual type.

The clamp 3 shown in FIG. 5 is to be detachably set by remote control from the ground without using a driving source, and is provided with left and right clamp shoes 3b for pressing the inner wall of the steel pipe pile.
Is connected to one end of an arm 3c with a pin 3d, and the arms are connected to each other with a pin 3e at the center of the steel pipe pile.
The spring 3f is arranged in the extension direction of the
A detachable rope 6 is attached to 3e, and each clamp shoe
A positioning rope 7 is attached to 3b. Both the detachable rope 6 and the positioning rope 7 are arranged so as to reach the ground via the top of the steel pipe pile, so that the clamp 3 can be freely set on the ground.

In the operation of attaching and detaching the clamp, when the clamp is moved, first, when the detachable rope is pulled, as shown in FIG. 6, the arm 3c uses the pin portions 3d and 3e as rotation axes by the weight of the clamp shoe 3b and the arm 3c. Rotate the clamp shoe
3b is drawn to the center of the steel pipe pile and detaches from the pipe wall. Next, after the clamp 3 is moved to a predetermined position by the positioning rope 7 in a state where the detachable rope 6 is pulled, when the detachable rope 6 is loosened, the clamp shoe 3b is moved by the expanding force of the spring 3f as shown in FIG. In the direction and presses against the tube wall to be clamped. In order to increase the pressing force, a weight 3g may be suspended from the pin connecting portion 3e of the arm 3c to increase its own weight as shown in the figure. Note that the clamp 3 may use a known means other than the above example.

As described above, the set position of the lightwave distance meter 4 (and the clamp 3) is set within the limit distance A within a certain range from the surface 2a of the inner soil of the pipe, so that stable measurement can be performed without being affected by the inner wall of the pipe. As a result, since the inclination s at the time of setting can be allowed to some extent, the setting operation is facilitated. For example, if a semiconductor laser having a diffusion characteristic of the light beam 5 of 10 m and 4 cm is used and a steel pipe pile is 1,000 mm in diameter and an inclination error s at the time of setting is 5 degrees with an inner diameter, the limit distance A at which the light wave beam 5 does not touch the pipe wall is A
Is about 6 m, so the lightwave distance meter 4 is set at a distance less than or equal to the soil surface 2a in the pipe. Under the same conditions, when the set-time tilt error is allowed twice, the limit distance A is about 13 m.

Incidentally, too much lightwave distance meter 4 (clamp 3)
Is set close to the soil surface of the pipe, the lightwave distance meter 4 (clamp 3) comes into contact with the soil surface 2a of the pipe due to the intrusion of the soil due to the penetration of steel pipe piles. It is not preferable because it needs to be performed frequently. In practical terms, it is desirable that the limit distance A be in a range of about 3 to 10 times the diameter of the steel pipe pile 1.

[0025]

FIG. 7 is a view showing an embodiment of a method for measuring soil 2 in a pipe in a steel pipe pile 1 constructed by a rotary press-fitting method. As shown in FIGS. 7a and 7b, the rotary press-fitting pile is an optical distance meter 4 set in the steel pipe pile 1 for rotary press-fitting an open-end steel pipe pile having a blade 8 on the outer surface at the lower end of the steel pipe pile.
Signal cannot be transmitted by wire to a measurement device on the ground. For this purpose, measurement data is wirelessly transmitted from the oscillator 9 provided at the top of the steel pipe pile to the receiver 10 on the ground.

Estimating the blockage rate from the relation between the soil height, the pipe soil, etc., which has been verified in advance, from the pipe soil height data during the penetration work of the steel pipe pile obtained by the above means. Can be.

Further, the state of the tip blockage can be estimated in real time from the relationship between the change in the soil height data obtained continuously and the change in the penetration amount of the steel pipe pile. In other words, when the soil height in the pipe increases in the same manner as the amount of penetration of the steel pipe pile, it is estimated that the tip end is in the open state (closure rate 0%), and the pipe is inserted despite the penetration of the steel pipe pile. If the soil height does not change and shows a constant value, the tip is closed (blocking rate 1
00%). The tip resistance of the steel pipe pile can be evaluated based on the closing rate.

[0028]

According to the present invention, it is possible to continuously measure the height of the soil in the pipe at the time of penetrating the open-ended steel pipe pile having the open end by the lightwave distance meter set in the pipe, so that the penetration of the pile is interrupted. Measurement work can be done safely without performing. According to the second aspect of the present invention, since the measurement is performed by setting the optical distance meter within a predetermined range from the surface of the soil in the pipe, the measurement can be stably performed without being affected by the pipe wall. Based on the obtained soil height data in the pipe, the closed state of the steel pipe pile tip can be accurately estimated and reflected in the evaluation of the steel pipe pile tip bearing capacity.
In particular, when the present invention is applied to the rotary press-in pile method, the evaluation of the tip support force during the penetration of the steel pipe pile can be accurately obtained in real time, and the steel pipe pile support force has a great effect.

[Brief description of the drawings]

FIG. 1A is a side sectional view showing an embodiment of a pipe soil height measuring method according to the present invention.

FIG. 2A is a side view illustrating a state of tube wall interference of a light wave beam (set error effect), and FIG. 2B is a side view illustrating a tube wall interference of a light wave beam (beam diffusion effect).

FIG. 3 is an explanatory diagram of a limit distance at the time of setting a lightwave distance meter.

FIG. 4 is an explanatory diagram of an example of setting a clamp.

FIG. 5 is an explanatory diagram of another clamp set example (at the time of setting).

FIG. 6 is an explanatory view of another clamp set example (at the time of detachment).

FIGS. 7A and 7B are a side view and a partially enlarged view of a tip of a steel pipe pile in which the present invention is applied to a rotary pile method.

FIG. 8 is a diagram showing an example of conventional soil height measurement in a pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel pipe pile 2 Pipe soil 2a Pipe soil surface 3 Clamp 4 Lightwave distance meter 5 Lightwave beam

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shigehiko Yamana 2-6-3 Otemachi, Chiyoda-ku, Tokyo New Nippon Steel Corporation F-term (reference) 2D050 AA06 CB04 EE00 2F065 AA24 BB08 BB24 CC40 DD06 FF31 GG06 HH04 JJ01 JJ15 TT02 UU03

Claims (3)

[Claims] 1. A method for measuring the height of soil in an open-ended steel pipe pile having an open end, comprising: setting a lightwave distance meter attached to a detachable clamp in the steel pipe pile, and penetrating the steel pipe pile into the ground. A method for measuring soil in a pipe at the time of construction of an open-ended steel pipe pile, wherein the height of soil invading the pipe is measured without contact. 2. The setting position of the lightwave distance meter is set within a limit distance related to a clamp setting error and a beam characteristic so that the lightwave beam does not interfere with the inner wall of the steel pipe pile. The method for measuring soil in pipes at the time of construction of the open-ended steel pipe piles described. 3. In a rotary press-fitting pile method in which an open-end steel pipe pile having a blade provided on an outer surface at a lower end portion of a steel pipe pile is rotary-pressed and penetrated, an optical distance meter attached to a detachable clamp is set in the steel pipe pile. The transmitter installed on the top of the steel pipe pile transmits the measurement data to the receiver on the ground by radio, and the non-contact measurement of the height of soil that enters the pipe when the steel pipe pile penetrates into the ground is performed. A method for measuring soil in a pipe at the time of constructing the open-ended steel pipe pile according to claim 1 or 2.