JP2004060282A - Structure or ground investigating method and investigating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and highly accurately estimate a position and a dimension of a cavity even in an accuracy-unexpectant place of a geophysical exploration technique without causing adverse influence on strength and administration to a structure or the ground. <P>SOLUTION: While excavating a hole in a cavity investigating object position in lining concrete C by a bit 2 of a rock drill 4 while keeping feed pressure and stroke pressure in a prescribed value, the existence and the size of the cavity V are estimated by a change in a hole excavating speed of the bit 2 and a torque load applied to the bit 2 at that time. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a structure for investigating the presence or absence, size, and position of a cavity formed between the inside of a structure and the surrounding ground, the state of deterioration of the structure itself, the property of the ground itself, and the like. The present invention relates to an object or ground survey method and apparatus.
[0002]
[Prior art]
When constructing a structure, the cavities that occur inside or around it have a significant effect on the strength and life of the structure, so it is generally required to find it early and ensure that it is filled. ing.
[0003]
It is important to calculate the amount of cavities in a structure in order to ensure that the cavities are filled, and nondestructive geophysical surveys such as electromagnetic wave radar, ultrasonic waves, and elastic waves have become commonplace.
There is also a method of estimating the condition of the ground by the drilling energy of a rock drill using the impact pressure, the number of impacts, and the drilling speed as parameters.
[0004]
[Problems to be solved by the invention]
However, in the example of the tunnel structure, when the lining concrete is thick (for example, 600 mm or more), when there is landslide on the back of the lining, when the back ground is loose, or when there is water accumulation, Errors increase due to attenuation of radio waves and ultrasonic waves. In addition, interpretation of the survey results depended on experienced persons, and the survey results lacked objectivity. These circumstances are common in existing tunnels, and consequently, geophysical exploration methods often cannot be expected to be accurate.However, there are no other appropriate survey methods, so the actual situation is to rely on geophysical exploration. .
In addition, even if a method of estimating the state of the ground by using the drilling energy is applied, the drilling energy is represented by a representative value obtained by combining the above-mentioned various parameters (each parameter is not evaluated, and is multiplied by one representative value. Therefore, it was difficult to estimate the detailed condition of the ground and structures.
[0005]
In recent years, due to the above-mentioned problems in the geophysical exploration method, it has also been practiced to actually drill holes in the lining by core boring to investigate the cavities. However, the method using the core boring has a disadvantage that the drilling speed is low and the survey cost is high. Therefore, a less expensive survey method has been required.
[0006]
In view of such circumstances, in the present invention, there is no adverse effect on the strength or management of the structure or the ground, and even in a place where the accuracy of the geophysical exploration method cannot be expected, it is simple and highly accurate. Estimate the presence / absence, size and position of cavities created inside or around the structure or the surrounding ground, the state of deterioration of the structure itself, etc., or the properties of the ground itself, including its position and size An object of the present invention is to provide a method and an apparatus for investigating a structure or the ground, which can be performed.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following solutions.
That is, the method for investigating a structure or the ground according to the first aspect is a method for investigating the inside of a structure or the state of the ground using a rock drill having a striking mechanism and a rotating mechanism. hand,
While drilling the survey position with the bit of the rock drill while maintaining the feed pressure and the impact pressure at the predetermined values, the change in the drilling speed of the bit and the torque load applied to the bit at that time changes the structure. It is characterized by investigating internal or ground conditions.
[0008]
The method for inspecting a structure or the ground according to claim 2 is the method according to claim 1, wherein
In addition to the change in the drilling speed of the bit and the torque load applied to the bit, the change in the pressure of the flushing air for discharging the dust generated when drilling by the bit changes the state of the inside of the structure or the ground. It is characterized by investigating.
[0009]
According to a third aspect of the present invention, there is provided a method for inspecting a structure or a ground,
When drilling with a rock drill bit cannot be performed while maintaining the feed pressure and the impact pressure at predetermined values, drilling was performed while gradually increasing the impact pressure, and the drilling speed exceeded the predetermined value. At the time, the drilling is performed while maintaining the impact pressure at that value, and the state of the inside of the structure or the ground is investigated.
[0010]
The method for inspecting a structure or ground according to claim 4 is the method according to any one of claims 1 to 3,
Instead of the change in the drilling speed of the bit, the change in the number of measurements per unit length of the drilling length of the bit when the number of measurements of the drilling length of the bit per unit time is set to a constant value, It is characterized by investigating the condition of the inside of the object or the ground.
[0011]
The method for inspecting a structure or the ground according to claim 5 is the method according to any one of claims 1 to 3,
With the change in the drilling speed of the bit, the change in the number of measurements of the drilling length of the bit per unit length when the number of measurements of the drilling length of the bit per unit time is set to a constant value, It is characterized by investigating internal or ground conditions.
[0012]
The method for investigating a structure or the ground according to claim 6 is the method according to any one of claims 1 to 3,
From the start of drilling of a structure, the drilling length of the bit is measured when the drilling speed of the bit rises above the preset upper limit speed value and the torque load falls below the preset lower limit torque value. Thus, the thickness dimension of the constituent material up to the cavity of the structure is estimated.
[0013]
The method for inspecting a structure or the ground according to claim 7 is the method according to any one of claims 1 to 3,
When investigating a cavity, when drilling with the bit, drilling of the bit when the drilling speed rises above a preset upper limit speed value and when the torque load falls below a preset lower limit torque value. The hole length is measured, and then the drilling with the bit is continued. The drilling of the bit when the drilling speed falls below the preset upper limit speed value and the torque load exceeds the preset lower limit torque value is performed. The method is characterized in that the hole length is measured, and the height of the cavity is estimated based on the difference between this value and the measured hole drilling length.
[0014]
The structure or ground survey device according to claim 8 is a structure or ground survey device for investigating the state of the inside of the structure or the ground using a rock drill having a striking mechanism and a rotating mechanism. hand,
The rock drill having a rod with a bit attached to the tip,
A moving mechanism for moving the rock drill in the longitudinal direction of the rod,
A moving distance measuring sensor for measuring the moving distance of the bit,
A torque sensor that measures the torque load applied to the drill bit during drilling,
It is characterized by having.
[0015]
The structure or ground survey device according to claim 9 is the device according to claim 8,
A flushing pressure measuring sensor for measuring a pressure of flushing air for discharging cutting dust generated when drilling by the bit is provided.
[0016]
The structure or ground survey device according to claim 10 is the device according to claim 8,
While controlling the operation of the rock drill and the movement mechanism, respectively, the movement amount measurement sensor, comprising a control device to which a detection value from the torque sensor is input,
The control device is configured such that, from the start of drilling, the drilling speed of the bit calculated from the measurement value of the movement amount measurement sensor is increased to or above a preset upper limit speed value, and the torque load is set to a preset lower limit torque. It is characterized in that it has a constituent material thickness measuring means for estimating the thickness dimension of the constituent material up to the cavity of the structure by measuring the drilling length of the bit when the bit falls below the value.
[0017]
The structure or ground survey device according to claim 11 is the device according to claim 8 or 10,
The control device, at the time of drilling with a bit, the drilling speed rises above a preset upper limit speed value, and the torque load falls below a preset lower limit torque value, and then drills with the bit. Subsequently, the drilling length of the bit when the drilling speed is lower than the preset upper limit speed value and the torque load exceeds the preset lower limit torque value is measured, and this value and the drilling length of the bit are measured. And a cavity dimension measuring means for estimating the height dimension of the cavity based on the difference between the two.
[0018]
When drilling with a rock drill, the drilling speed of the bit and the torque load applied to the bit vary depending on the material to be drilled. For this reason, if the drilling speed and the torque load applied to the bit when drilling various materials with the bit are examined in advance by experiments, etc., the drilling speed and torque of the bit are actually determined when drilling. By examining the load, the drilling material at that time can be determined.
The present invention utilizes this, and detects or calculates the drilling speed of the bit and the torque load applied to the bit, and compares them with data obtained in advance to determine the material of the drilled portion. It can be estimated whether or not there is a cavity at the drilling location, and also how large the cavity is, including its position. This makes it possible to detect the presence of a cavity or the like only by forming a hole having a very small diameter as compared with the case where core boring is performed.
[0019]
As a reference for estimating what the material of the drilled portion is or whether there is a cavity in the drilled portion, etc., in addition to or in addition to the drilling speed of the bit and the torque load applied to the bit. Instead of the pressure of the flushing air for discharging the cuttings generated when drilling with the bit, the drilling length of the bit when the number of measurements of the drilling length of the bit per unit time are set to be constant The number of measurements per unit length can also be used.
[0020]
In addition, the relationship between the drilling speed and the number of measurements is the opposite relationship that the number of measurements decreases as the drilling speed increases, and the number of measurements increases as the drilling speed decreases. When the speed is low, the change in the speed is inconspicuous, but the change in the number of times of measurement may be apparent, and the use of these two is convenient in terms of complementing each other.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a situation in which a structure or ground survey device 1 according to an embodiment of the present invention is applied to a survey of a cavity V on the back of a lining concrete C of an existing tunnel.
[0022]
The investigation device 1 shown in the figure supports a rod 3 having a bit 2 at the tip, a rock drill 4 having a striking mechanism for striking the rod 3 and a rotation mechanism for rotating the rod 3, respectively, and a rock drill 4. And a control device 6 for controlling the operation and the like of the rock drill 4.
[0023]
In this investigation device 1, a bit 2 having a diameter much smaller than that of a normal boring (for example, a bit having a diameter of 33 mm) is used.
[0024]
Further, between the guide shell 5 and the rock drill 4, there is provided a moving mechanism 7 capable of moving the rock drill 4 back and forth in the drilling direction. The extending direction of the guide shell 5 is set to be the same as the drilling direction of the rock drill 4, and the rock drill 4 moves while hitting and rotating the rod 3. The lining concrete C can be drilled by the bit 2 attached to the tip.
[0025]
The movement mechanism 7 is provided with a movement amount measuring sensor 10 that can remotely measure the position of the rock drill 4 on the guide shell 5. At the time of drilling, the distance from the initial position of the rock drill to the current position is equivalent to the amount of movement of the bit 2, that is, the drilling length of the bit 2. The hole length of No. 2 is also measured.
[0026]
Further, the rock drill 4 has a torque sensor 11 for detecting a torque load acting on the rod 3 when the rod 3 is rotated, and an air discharge hole (not shown) of the bit 2 for discharging cuttings when drilling. Pressure sensor 12 for detecting the pressure of the flushing air discharged from the apparatus, and the number of movements of the rock drill 4 measured by the movement amount measurement sensor 10 is kept constant (for example, 5 times / second) per unit time. A measurement frequency detection mechanism 13 is provided to count the number of measurements per unit length of the movement amount of the rock drill 4 (in other words, the drilling length of the bit 2) when set. The sensors 11 and 12 and the number-of-measurements detection mechanism 13 and the like are electrically connected to the control device 6 similarly to the movement mechanism 7 and the movement amount measurement sensor 10.
[0027]
In addition, the rock drill 4 also includes a striking device for measuring the striking pressure of a hydraulic or air source that drives a striking mechanism of the rock drill 4 when drilling the lining concrete C of the existing tunnel with the rod 3. A pressure sensor 14 and a feed pressure sensor 15 for measuring a feed pressure of a hydraulic source or an air source for driving a cylinder that slides the rock drill 4 in the front-rear direction are installed, respectively. Is electrically connected to Then, at the time of drilling, the rock drill 4 moves forward and backward through the moving mechanism 4 while controlling the impact pressure and the feed pressure to be constant values based on the flowchart shown in FIG. Be driven.
[0028]
The control device 6 controls the operation of the rock drill 4 and the moving mechanism 7, respectively, and includes a structure, for example, the thickness of the lining concrete C from the inner peripheral surface of the existing tunnel to the cavity V. A component material thickness measuring means 6a for estimating the dimension Ch and a cavity dimension measuring means 6b for estimating the height dimension Vh of the cavity V are provided. The details of the constituent material thickness measuring means 6a and the cavity size measuring means 6b will be clarified in the description of the investigation method described later.
[0029]
Next, a method of inspecting a structure or the ground using the inspection device 1 will be described.
For this, first, the bit 2 at the tip of the rod 3 is brought into contact with the lining concrete C by the rock drill moving mechanism 7, and the rod 6 is controlled by the control device 6 while controlling the impact pressure and the feed pressure. 3 is driven to rotate to start drilling of the lining concrete C.
[0030]
The processing procedure of the control device 6 in this case is shown in the flowchart of FIG.
First, when drilling is started (step 1), the control device 6 cuts the drilling while maintaining the impact pressure at a preset minimum value (for example, 2 Mpa) and the feed pressure at a preset constant value (for example, 5 Mpa). Start the hole (step 2).
[0031]
Here, it is determined whether or not the drilling proceeds, specifically, whether or not the drilling speed by the bit 2 exceeds a predetermined value (Step 3). Is increased by a certain amount to increase drilling efficiency. (Step 4) If the drilling still does not proceed, the impact pressure is further increased by a certain amount. Then, the impact pressure is continuously increased until drilling proceeds (steps 3 and 4).
[0032]
When drilling proceeds, that is, when the drilling speed exceeds a predetermined value, drilling is continued while maintaining the feed pressure and the impact pressure at the values at that time (step 5). As the drilling proceeds, measurement of the drilling length, drilling speed, flushing pressure, and the number of measurements during drilling is started. That is, the drilling length by the bit 2 is measured by the moving amount measuring sensor 10, the drilling speed is obtained by dividing the drilling length by the time, the flushing pressure is measured by the flushing pressure sensor 12, and the number of times of measurement is measured. The number of measurements per unit length of the drilling length of the bit 2 obtained by the detection mechanism 13 is obtained. Then, while the mechanical data is stored in a storage unit (not shown), the transition of the values is examined, and the extent to which the values have changed is also examined (step 6).
[0033]
Here, before it is determined that the concrete has passed through the lining concrete C, which will be described later, if the drilling speed becomes very small and the number of measurements suddenly increases so as to protrude as shown in FIG. The control device 6 determines that drilling has become impossible when the bit 2 is reinforced with steel or steel in the lining concrete C.
In this case, since it is difficult to make a further drilling, the moving mechanism 7 is driven to pull out the bit 2 from the lining concrete C via the rod 3 and the investigating device 1 is mounted on the support table (not shown). The inside of the tunnel is moved together with the guide shell 5, and the process returns to the start of step 1 of the flowchart again to start drilling of another portion.
[0034]
Also, for example, while drilling the lining concrete C, the tendency of other mechanical data such as torque load and flushing pressure does not change, but the drilling speed slightly increases as shown in (b) in FIG. Determines that the strength of the lining concrete C has deteriorated.
[0035]
As described above, the drilling in the lining concrete C is continued, but if the bit 2 at the tip of the rod 3 penetrates the lining concrete C, the drilling speed increases rapidly as shown in FIG. Decreases sharply. In this case, the control device 6 determines that the bit 2 has penetrated the lining concrete C, and further determines the position of the rock drill 4 on the guide shell by the moving mechanism 7 at this time by the output of the moving amount measurement sensor 10. Measure based on the signal. Further, the control device 6 determines the difference between the measured value and the previously measured position of the rock drill 4 at the start of drilling by the built-in material thickness measuring means 6a. The thickness Ch is stored in a storage unit (not shown).
[0036]
If the controller 6 determines that the concrete C has passed through the lining concrete C, it means that a new object has been detected on the flowchart of FIG. 2 (step 7), and the process returns to step 2. At this time, if the impact pressure is set to a value larger than the preset minimum value in order to remove the lining concrete C, the impact pressure is returned to the minimum value again, and the feed pressure is set to a predetermined value. Maintain a constant value and start drilling under these conditions.
[0037]
In this situation, when the drilling speed increases to a value equal to or higher than a preset upper limit speed value and the torque load decreases to a value equal to or less than a preset lower limit torque value, the control device 6 determines that the drilling target position by the bit 2 is the cavity V Is determined to have been reached.
It should be noted that the upper limit speed value and the lower limit torque value were obtained by conducting various experiments using the rock drill 4 and the bit 2 penetrating the ground or lining concrete, and the tip of the bit 2 was merely applied to a fluid such as air or water. Data in the case of no contact is taken, and an appropriate value is determined in advance based on these data values.
[0038]
When the drilling is continued in the same state, the drilling speed falls below the upper limit speed value, and the torque load exceeds the lower limit torque value, the control device 6 determines that the bit 2 has passed through the cavity V. The position of the rock drill 4 on the guide shell 5 at that time is measured based on the detection value of the movement amount measurement sensor 10.
[0039]
Further, the control device 6 determines the difference between the measured value and the position of the rock drill 4 when it is determined that the rock drill 4 has entered the previously measured cavity V by the built-in cavity size measuring means 6b. The length Vh is stored in a storage unit (not shown).
[0040]
On the other hand, after it is determined that the concrete has passed through the lining concrete C, if the drilling speed increases but does not increase to near the upper limit speed value, and the torque load also decreases but does not reach near the lower limit torque value, the back surface of the lining concrete C Determines that there is no cavity V. When the flushing pressure detected by the flushing pressure sensor 12 is increased, the material at the position where the tip of the bit 2 contacts is different from the material of the lining concrete C, and is soft and easily closed at the tip of the bit. For example, it is determined that the ground is viscous. By the way, when the ground G is sandy, the flushing pressure does not increase so much.
[0041]
While drilling with the bit 2 as described above, while measuring mechanical data such as drilling length, drilling speed, flushing pressure, and the number of measurements during drilling, and examining how those values change. A cavity survey was conducted on the back of the lining concrete C of the existing tunnel. In this survey, the drilling length by the bit 2 was determined by the maximum drilling length determined by the function of the rock drill 4 and the length of the rod 3 and the guide shell 5. The drilling is performed until the length reaches the maximum drilling length (steps 5, 6, 8), and when the drilling length reaches the maximum drilling length, the drilling is terminated (step 9).
[0042]
In the investigation method described above, the cavity inspection target position is drilled using the bit 2 attached to the tip of the rod 3, while the drilling speed of the drilling hole, the torque load, the flushing pressure, and the like are changed. Since the presence / absence and the size thereof are estimated, the existence of the cavity V can be detected accurately only by forming a hole having a very small diameter as compared with the case where core boring is performed. Thus, a high-accuracy cavity inspection can be performed at low cost and without any management problem.
[0043]
In addition, in the above-described investigation method, the thickness dimension Ch of the lining concrete C is measured by measuring the moving dimension of the rock drilling machine from the start of drilling until the drilling speed and the torque load are both suddenly changed. I am trying to do it. When the drilling speed increases to a value equal to or higher than a preset upper limit speed value and the torque load decreases to a value equal to or less than the preset lower limit torque value, it is determined that the cavity V has been entered. If the torque load falls below the value and the torque load rises above the lower limit torque value, the height Vh of the cavity V is estimated from the position at the time of the change. In this manner, the thickness Ch of the lining concrete C and the height Vh of the cavity V can be directly detected, and the physical exploration or the like can be performed without being affected by the physical properties of the ground G. The survey can be conducted with higher accuracy than that of the survey.
[0044]
Further, at the time of drilling, even if the impact pressure is increased, if the drilling speed is very small and increases rapidly so that the number of measurements is prominent, stop drilling and drill a hole at another location. Therefore, it is possible to investigate the cavity V at an appropriate location while avoiding the support works, the reinforcing bars, and the like.
[0045]
In addition, the above-described investigation device 1 uses the control device 6 to cover the cavity V based on the difference in the position of the rock drill 4 from the start of drilling until the drilling speed sharply increases and the torque load sharply decreases. The thickness Ch of the concrete thickness is measured, and the cavity is determined based on the difference in the position of the rock drill 4 until the drilling speed decreases and the torque load increases after entering the cavity V. Since the height V of the V is measured, the thickness Ch of the lining concrete C and the size of the cavity V can be automatically detected, and an efficient investigation can be performed. .
[0046]
In addition, when it is estimated that there is a cavity V, an existing inspection hole communicating with the cavity V is replaced with an enlarged bit (not shown) having a diameter larger than the bit 2 used for drilling the inspection hole. By using and expanding the diameter, a grout injection hole as shown by 20 in FIG. 1 can be obtained. In this case, since the grout injection hole 20 is obtained by using the existing investigation hole, the vibration can be reduced by the centering effect and the construction period can be shortened as compared with the case where the grout injection hole is formed directly by a rock drill. be able to.
[0047]
In the above-described embodiment, the present invention has been described by taking the case of tunnel lining as an example. However, the investigation target by the investigation device 1 according to the present invention is not limited to an existing tunnel, and other concrete structures may be used. Alternatively, it may be a structure made of another material or the ground itself. In short, if the survey target is to investigate the presence or absence, size and location of cavities created inside the structure or between the ground, the state of deterioration of the structure itself, the properties of the ground itself, etc. The invention is fully applicable.
.
For example, when investigating the condition of the basement of a building, for example, the thickness of the underground side wall, the width of the cavity, and the width of the ground that are adjacent to each other can be estimated by using the above-described investigation method.
[0048]
In the above-described embodiment, when performing the cavity survey, the presence or absence of the cavity and its size are mainly estimated based on the respective changes in the drilling speed of the bit 2 and the torque load applied to the bit 2 during drilling. However, instead of or in addition to the drilling speed of the bit 2, when the measured number of drilling lengths of the bit per unit time is set to be constant, the drilling length of the bit per unit length is set. The presence or absence of the cavity V may be estimated based on the change in the number of measurements.
[0049]
【The invention's effect】
As described above, according to the present invention, it is possible to detect the presence of a cavity accurately and in a short time only by forming a hole having a very small diameter as compared with a case where core boring is performed when performing a cavity survey. Can be.
This makes it possible to perform a high-accuracy cavity inspection in a short period of time at low cost and without any management problems.
In addition, since it is possible to directly detect the thickness dimension and the size of the cavity of the structural material of the structure or the ground, high-precision surveys can be performed regardless of the physical properties of the structure or the ground or its surroundings. It is possible to carry out the survey while also avoiding obstacles such as structural materials.
Also, by taking into account the change in the pressure of the flushing air, it is possible to estimate the material of the structure and the ground. In addition, by setting the percussion pressure to a suitably high value, the drilling speed can be increased, and drilling of hard materials can be performed, increasing the degree of freedom of investigation and shortening the period for investigation. it can. Also, as the data for estimation, if the number of measurements per unit length of the drilling length of the bit when the number of measurements of the drilling length of the bit per unit time is set to a constant, higher accuracy can be achieved. A survey can be conducted. Furthermore, when it is presumed that there is a cavity, if the existing investigation hole communicating with this cavity is expanded using a diameter expansion bit to obtain a grout injection hole, grout injection can be performed directly by a rock drill. Vibration can be reduced as compared with the case of forming a hole, and the period for forming the injection hole can be shortened.
[Brief description of the drawings]
FIG. 1 is an elevational sectional view showing a situation when investigating a cavity of an existing tunnel by an investigation device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a processing procedure of a control device in the investigation device shown in FIG.
FIG. 3 is an explanatory diagram showing the relationship between mechanical data and the state of the lining concrete and the cavities and ground at the back thereof when the cavity of the existing tunnel is investigated by the investigation device shown in FIG. 1;
[Explanation of symbols]
Reference Signs List 1 investigation device 2 bit 3 rod 4 rock drill 5 rock drill 5 guide shell 6 control device 6a constituent material thickness measuring means 6b cavity size measuring means 7 moving mechanism 10 moving amount measuring sensor 11 torque sensor 13 measurement number detecting mechanism 14 impact pressure sensor 15 feed Pressure sensor C Lining concrete V Cavity

Claims (11)

A method for investigating a structure or ground using a rock drill having a striking mechanism and a rotating mechanism to investigate the state of the inside of the structure or the ground,
While drilling the survey position with the bit of the rock drill while maintaining the feed pressure and the impact pressure at the predetermined values, the change in the drilling speed of the bit and the torque load applied to the bit at that time changes the structure. A method for investigating a structure or ground, wherein the state of the inside or the ground is investigated. In the method for inspecting a structure or the ground according to claim 1,
In addition to the change in the drilling speed of the bit and the torque load applied to the bit, the change in the pressure of the flushing air for discharging the dust generated when drilling by the bit changes the state of the inside of the structure or the ground. A method for investigating a structure or ground characterized by investigating. In the method for investigating a structure or ground according to claim 1 or 2,
When drilling with the bit of the rock drill while maintaining the feed pressure and the percussion pressure at predetermined values cannot be performed, drilling was performed while gradually increasing the percussion pressure, so that the perforation speed exceeded the predetermined value. A method for investigating a structure or the ground, characterized by drilling while maintaining the percussion pressure at that point, and investigating the state of the inside of the structure or the ground. In the structure or ground survey method according to any one of claims 1 to 3,
Instead of the change in the drilling speed of the bit, the change in the number of measurements per unit length of the drilling length of the bit when the number of measurements of the drilling length of the bit per unit time is set to a constant value, A method for investigating a structure or a ground, characterized by investigating the state of the inside of the object or the ground. In the structure or ground survey method according to any one of claims 1 to 3,
With the change in the drilling speed of the bit, the change in the number of measurements of the drilling length of the bit per unit length when the number of measurements of the drilling length of the bit per unit time is set to a constant value, A method for investigating a structure or ground, wherein the state of the inside or the ground is investigated. In the structure or ground survey method according to any one of claims 1 to 3,
From the start of drilling of a structure, the drilling length of the bit is measured when the drilling speed of the bit rises above the preset upper limit speed value and the torque load falls below the preset lower limit torque value. A method of estimating a thickness of a constituent material up to a cavity of the structure. In the structure or ground survey method according to any one of claims 1 to 3,
When investigating a cavity, when drilling with the bit, drilling of the bit when the drilling speed rises above a preset upper limit speed value and when the torque load falls below a preset lower limit torque value. The hole length is measured, and then the drilling with the bit is continued. The drilling of the bit when the drilling speed falls below the preset upper limit speed value and the torque load exceeds the preset lower limit torque value is performed. A method for investigating a structure or ground, comprising measuring a hole length, and estimating a height of a cavity based on a difference between the value and the measured drilling length of a bit. A structure or ground investigation device for investigating a state of the inside of a structure or a ground using a rock drill having a hitting mechanism and a rotation mechanism,
The rock drill having a rod with a bit attached to the tip,
A moving mechanism for moving the rock drill in the longitudinal direction of the rod,
A moving distance measuring sensor for measuring the moving distance of the bit,
A torque sensor that measures the torque load applied to the drill bit during drilling,
An investigation device for a structure or ground, comprising: The structure or ground survey device according to claim 8,
A structure or ground surveying device, comprising: a flushing pressure measurement sensor for measuring a pressure of flushing air for discharging cutting dust generated when drilling by the bit. The structure or ground survey device according to claim 8,
While controlling the operation of the rock drill and the movement mechanism, respectively, the movement amount measurement sensor, comprising a control device to which a detection value from the torque sensor is input,
The control device is configured such that, from the start of drilling, the drilling speed of the bit calculated from the measurement value of the movement amount measurement sensor is increased to or above a preset upper limit speed value, and the torque load is set to a preset lower limit torque. A structure or ground having component material thickness measuring means for estimating the thickness dimension of the component material up to the cavity of the structure by measuring the drilling length of the bit when the bit falls below the value. Survey equipment. The structure or ground survey device according to claim 8 or 10,
The control device, at the time of drilling with a bit, the drilling speed rises above a preset upper limit speed value, and the torque load falls below a preset lower limit torque value, and then drills with the bit. Subsequently, the drilling length of the bit when the drilling speed is lower than the preset upper limit speed value and the torque load exceeds the preset lower limit torque value is measured, and this value and the drilling length of the bit are measured. A cavity or dimension measuring device for estimating a height of a cavity based on a difference between the surveying device and the ground.

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