JP3167048B2 - Setting method of friability evaluation standard of rock mass and its setting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for setting a standard for evaluating the friability of a rock mass.
The present invention relates to a method of setting a crushability evaluation criterion of an upper rock layer and an improvement of a setting device for selecting a suitable construction machine model prior to crushing such as excavation of the upper rock layer.

[0002]

2. Description of the Related Art Conventionally, in various large-scale works such as dams, buildings, tunnels and bridges, in order to know the amount of construction machines and the number of machines that are optimally sized for the work site, it is necessary to know the amount of earth work and the amount of work. Knowing the bearing capacity and friability of the rock and ground at each point on the site is an essential requirement for the subsequent construction. In order to know the friability of this rock mass, the following method has been adopted as a method of setting the friability evaluation standard for the upper rock mass. There are methods based on elastic wave velocity, methods based on crack coefficient, methods based on reconnaissance, methods based on strength tests, methods based on RQD, and the like. In the above, for example, skilled workers who vary in actual crushing amount are required. However, there are disadvantages and problems, such as the fact that they are not suitable for the site. For this reason, the present inventor has previously proposed in Japanese Patent Application No. Hei 1-213262 a method of setting the friability evaluation standard for the upper layer of the rock using the equal pressure distribution loading method of the in-hole loading test.

[0003]

However, in the in-hole loading tester using the equal pressure distribution loading method proposed in Japanese Patent Application No. Hei 1-213262, when setting the friability evaluation standard for the upper layer of rock, drilling from the upper surface of rock is performed. After drilling the hole, the probe of the in-hole loading tester is placed in the hole, and the load is intermittently applied to the peripheral wall of the hole by the probe, and the hole is loaded in an ascending manner, and the radius Rm in the hole,
Load Δp and displacement Δr and Poisson's ratio ν of rock
From equation, the rock deformation coefficient Db (II) is calculated by the following equation: [Db (II)
= (1 + ν) × Rm × (Δp / Δr)], and the rock deformation coefficient Db (II) is used as an index of the friability evaluation standard of the upper layer of the rock, so that the Poisson's ratio ν of the rock can be calculated,
Since it is necessary to measure a large number of displacement amounts Δr with respect to the applied load Δp, it is necessary to have the knowledge to obtain the Poisson's ratio ν of the rock mass, and it takes a lot of man-hours to measure many points on a large large work site. There is still a problem.

The present invention focuses on the above-mentioned conventional problems and relates to a method for setting a friability evaluation standard for an upper layer of rock and a device for selecting the same. The purpose of the present invention is to provide a method of setting the friability evaluation standard for the upper layer of the rock and the improvement of the setting device for selecting the model.

[0005]

In order to achieve the above object, according to a first aspect of the present invention, a standard for evaluating the friability of an upper layer of a rock mass is set by an in-hole loading tester using an equal pressure distribution loading method. Then, drill a boring hole from the top of the rock, put the probe of the in-hole loading tester in the hole, and change the radius in the hole by intermittently loading the hole peripheral wall with the probe and increasing the load. By measuring the change, in the method of setting the friability evaluation criteria for the upper layer of rock, the displacement at the point where the change in the displacement changes linearly with the change in the load and the load on the extension of the straight line are zero. The difference from the initial displacement at the time of is obtained, and the crushing strength of the rock is obtained from the magnitude of the difference.

Further, in the second invention, a borehole is drilled from the upper surface of the rock, and the hole is bored in the hole by the in-hole loading tester using the uniform pressure distribution loading method to set the friability evaluation standard of the upper layer of the rock. Put the probe of the loading tester, intermittently and gradually increase the load on the peripheral wall of the hole by the probe, change the radius in the hole, and measure the change to measure the friability of the upper layer of rock In the setting method, the displacement (δ) when the probe abuts on the peripheral wall of the hole with respect to the change in the load, the displacement (δif) when the displacement with respect to the load changes linearly, and the load (Pif) ), And the difference in displacement amount per load (Pif) [(δif)
− (Δ)] to determine the crushing strength of the rock mass.

[0007] In the third invention mainly based on the first invention or the second invention, the crushing strength of the rock is determined by the displacement (mm) per kilogram / square centimeter of the applied load.

Further, in the fourth invention, a pressure source 1 of an in-hole loading tester using a uniform pressure distribution loading method, a probe 3 made of a rubber tube or the like inserted into the hole and expanding the hole,
A standard device for evaluating the friability of the upper layer of rock, comprising a pressure gauge 5 for measuring the pressure applied to the probe 3 and a displacement meter 7 built in the probe 3 and measuring the displacement in the hole due to the pressure applied to the probe 3. And a storage device for storing the applicable model of the construction machine with respect to the crushing strength of the rock mass, and a signal from the pressure gauge 5 and the displacement gauge 7 to load the deformation amount of the displacement point shifting to a straight line and the extension of the straight line. Calculate the difference between the displacement amount when the weight is zero, or the ratio to the difference between the displacement amount of the applied load and the displacement amount when the applied load is zero with respect to the applied load at an arbitrary point on the linear portion. The arithmetic unit 9 for determining the crushing strength of the rock mass according to the magnitude of the difference or the ratio, comparing the crushing strength of the rock mass with the obtained crushing strength of the rock mass, and selecting several kinds of construction machines that are suitable, and the selected several types Select a model from among compatible models And a display device 10 for displaying the so that.

[0009]

According to the above construction, in the in-hole loading test of the equal distribution loading method using the boring hole, the cylindrical rubber tube is expanded by the fluid to uniformly press the boring hole wall in all directions. As shown in FIG. 5, initially, there is a slight amount of clearance between the rubber tube and the boring hole, so that only a slight amount of displacement (point A) increases. Next, after coming into contact with the hole wall, the vicinity of the surface is plastically deformed in a curved manner to a point (B), and after that, when the point (B) is exceeded, the load strength (pressure)
And the displacement changes almost linearly and shows an elastic behavior. At this time, the change in the displacement amount after hitting the hole wall is illustrated, the equation of the line segment at the point (B) where the change changes linearly is obtained, and the displacement amount δo of the extension line of the equation of the line segment is obtained. Is obtained, and the difference from the displacement amount δi corresponding to the load Pi is obtained to obtain the hole displacement amount δ, and this value is used as excavation evaluation. The crushing strength of the rock such as hard geology and soft geology is determined according to the size.

In addition, instead of the displacement δo of the extension line, the pressure at the position of the slight displacement (point A) at which a small amount of clearance between the rubber tube and the boring hole disappears increases the pressure against the hole wall. The amount of displacement δ to be started is measured, and thereafter, a load is applied, and the displacement at an arbitrary point where the change linearly changes is obtained, and the load at that time is obtained. From the difference between these two displacements and the ratio of the applied load at that time,
The value of the ratio is used as excavation evaluation. The crushing strength of the rock such as hard geology and soft geology is determined according to the magnitude of the ratio.

[0011] The site of the rock crush strength obtained above is excavated with several types of actual construction machines, the work amount of each of the construction machines is measured, and the rock crush strength obtained by the above method and the excavated construction strength are measured. Determine the correlation with the work volume of the machine, store it in a personal computer, measure the crushing strength of the rock at the new work site, and adapt to the crushing strength of the rock or the site to be introduced from the construction period etc. You can select the construction machine or the number.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for setting the evaluation standard for friability of the upper layer of rock and the apparatus for selecting the same according to the present invention will be described.
This will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an apparatus for selecting a friability evaluation standard for a rock upper layer according to the present invention, and FIG. 2 is a block diagram. In FIG. 1 and FIG. 2, the in-hole loading tester 50 of the measuring device for the friability evaluation standard is used.
Measures a pressure source 1 of an in-hole loading tester using an equal pressure distribution loading method, a probe 3 made of a rubber tube or the like inserted into the hole and expanding the hole, and a pressure applied to the probe 3. A pressure gauge 5, a displacement gauge 7 for measuring the displacement of the hole by the pressure applied to the probe 3, and a displacement of a point of the linear portion and an initial displacement by a signal from the pressure gauge 5 and the displacement gauge 7. The personal computer 10 calculates the difference, obtains the crushing strength of the bedrock from the magnitude of the difference, and displays an applicable model of the construction machine with respect to the crushing strength of the bedrock.

The pressure source 1 is provided with a pump 1a which is driven manually and electrically, and a relief valve 1b for setting a pressure. When the pump 1a and the relief valve 1b operate electrically, the pump starts according to a command from the personal computer 10, and the pressure of the relief valve 1b increases. In addition, it is configured so that a human can operate when manually operated. The pressure gauge 5 and the displacement gauge 7 are provided with a measuring device 8 for measuring pressure and displacement based on a signal from a sensor and accumulating data, and transmit the measured data to the personal computer 10.

As shown in FIG. 2, the personal computer 10 comprises a RAM 11, a ROM 12, a CPU 13, a timer 14, and an I / O 15. I / O
15 is a measurement mode setting means 1 for setting a measurement mode.
7, a load setting means 18 for setting an interval of the load,
A load holding time setting means 19 for setting a holding time until the load stabilizes is additionally provided. Also, I / O1
Signals from the pressure gauge 5 and the displacement gauge 7 are input to 5, and signals from the I / O 15 to the pump driving means 21, the load driving means 22, and the display means 23 are output.

The in-hole loading tester 50 inserts the probe 3 into a boring hole 53 having a diameter of 65 to 75 mm which has been previously drilled in a rock 51 at a work site to be measured by a drill or drill. A pressure source 1 is placed in a rubber tube 31 via a high-pressure rubber hose 32.
The rubber tube 31 expanded by this fluid pressure uniformly presses the inner wall of the hole 53 in all directions. In addition, the in-hole loading tester 50
A pressure gauge 5 such as a semiconductor pressure sensor and a caliper type displacement gauge 7 for measuring the displacement of the probe 3 in accordance with the displacement in the hole with respect to the pressure applied to the probe 3 are housed in the inside. I have.

Next, the operation of the above configuration will be described. The first embodiment will be described with reference to the flowchart of FIG. First, in step 1, the probe 3 is inserted into a hole already drilled. In step 2, a measurement mode is selected by the measurement mode setting means 17. For the measurement mode selection, for example, in the case of mode 1, the first embodiment described below can be selected, in mode 2, the second embodiment can be selected, and in mode 3, the method proposed in Japanese Patent Application No. Hei 1-213262 is proposed. ,
In Mode 4, the method is selected according to the requirements such as the method of manually applying a load, the size of the measurement site, the number of measurement points, or the accuracy of the measurement data.

In step 3, an intermittent and increasing load is applied to the probe 3 from the pressure source 1. For example, as shown in FIG.
At this time, the horizontal axis represents time (seconds), and the vertical axis represents the applied load (Kg /
cm ² ), Ptm in the figure indicates the same load holding period (second), and Ptn indicates the respective load (Kg / c).
m ² ). In step 4, it is determined whether the load has become constant. At this time, the same load holding period Ptm is required to secure at least 25 seconds or more irrespective of the type of the rock, because the rock strain is stabilized every time each load Ptn is loaded on the rock. Is good. On the other hand, the applied load Ptn may be, for example, every 5 kg / cm ^2, every 10 kg / cm ² , or a combination thereof. Load P
tn is input by the load setting means 18 for setting the interval of the load. The same load holding period Ptm is input by the load holding time setting means 19 for setting a holding time until the load stabilizes.

In step 5, the applied load Ptn is measured by a pressure gauge and transmitted to the personal computer 10 via the measuring device 8 as a pressure ΔP as shown in FIG. At this time, a command for measuring the displacement is issued. In step 6,
Similarly, the displacement amount Δr measured by the displacement meter 7 is transmitted to the personal computer 10 via the measuring device 8. In step 6, the transmitted data (pressure ΔP, displacement Δr) is stored and calculated by the personal computer 10.

In step 7, the previous change rate (ΔP / Δ
r) and the current change rate (ΔP / Δr), that is, the change rate of the displacement amount δin with respect to the n-th load Pin, and the displacement with respect to the previous (n−1) -th load Pi (n−1) times The rate of change of the quantity δi (n-1) n is compared to determine whether the difference is within a predetermined quantity. If not, return to step 3 and apply the next pressure to the probe. If it is within the predetermined amount, it is determined that the point shifts to a straight line, and in step 8, the line segment equation and the initial change amount δo of the hole are obtained. At this time,
As shown in FIG. 5, the change in the displacement amount after hitting the hole wall is illustrated, and the change (B)
And the line segment of C) are obtained, and the displacement amount of the extension line of the line segment formula, that is, the initial displacement amount δo when the applied load Ptn is zero is obtained.
(Point C) is obtained. At this time, the point (point B) where the change in the displacement amount changes linearly is defined as the displacement amount δi corresponding to the applied load Pi. The difference between the displacement δi at the point where the change of the displacement changes linearly and the initial displacement δo when the applied load Ptn is zero is obtained, and the displacement δ of the hole is obtained. That is, the crushing strength is used as the crushing strength of the rock, and the friability evaluation value is obtained according to the magnitude. For example, in the case of soft geology, as shown in FIG. 6, the displacement amount δis at a point that changes linearly with the load Pis increases, and the gradient of the line equation (a) decreases. Quantity δs
Also increases. In the case of hard geology, as shown in FIG.
Displacement δi at a point that changes linearly with applied load Pih
As h decreases, the gradient of the line segment equation (b) increases, and the displacement δh also decreases.

Next, a description will be given of an experimental example in which measured values at work sites in various places are compared with the work amount of a construction machine (power shovel). (1) Experimental example, FIG. 8 shows the correlation between the displacement δ (mm) of the hole and the work per hour (m3 / hour H) for the model of the power shovel [model: name of Komatsu Ltd.]. Show. For example, N
In o1, the power shovel PC400 manufactured by Komatsu Ltd.
Work site: 265m3 when measured at Yamakita-machi, Ashigara-kami-gun, Kanagawa
/ One hour H, which indicates that the hole displacement amount δ of the friability evaluation value according to the present invention is 4.89 mm. This is when measured at not Ken, displacement δ
Was 0.90 mm, the work amount was 0 m @ 3 / hour H, and no work was possible. Further, when the PC650 ripper was put into the above site, a working amount of 104 m3 / hour H was obtained. The above comparison is proportional <br/> compare with pure drilling operation amount per unit time. Therefore, the actual excavation amount per cycle time of actual excavation is lower than this. The recommended value of the work amount is approximately 150 m3 / hour H as a reference value. Therefore, it is clear that a model of 150 m @ 3 / hour H should be introduced at the site.

Next, the operation of the second embodiment will be described. The second embodiment will be described with reference to the flowchart of FIG. First, in step 11, the probe 3 is inserted into a hole already drilled. In step 12, for example, the second embodiment of mode 2 is selected by the measurement mode setting means 17. In step 13, an intermittent and increasing load is applied to the probe 3 from the pressure source 1. Step 14
Then, it is determined whether the pressure applied to the probe 3 due to the contact of the probe 3 with the hole wall of the boring hole 53 has changed, that is, whether or not the pressure has become substantially zero or more. If not, the process is repeated until the pressure starts to rise by contacting the hole wall.

When it has risen, the displacement amount δ (shown in FIG. 10) at that time is measured in step 15 and transmitted to the personal computer 10 via the measuring device 8. In step 16, an intermittent and increasing load is applied to the probe 3 from the pressure source 1. The loading at this time is performed in the same manner as in the first embodiment. In step 17, it is determined whether the load has become constant. In step 18, the applied load Ptn is measured with a pressure gauge, and as shown in FIG.
Through the measuring device 8 as P, the personal computer 10
Sent to. At this time, a command for measuring the displacement is issued.

In step 18, the displacement Δr measured by the displacement meter 7 is also transmitted to the personal computer 10 via the measuring device 8. In step 19, the transmitted data (pressure ΔP,
The displacement amount Δr) is stored and calculated. In step 20, the previous (n-1) th change rate (ΔP / Δr)
And the n-th change rate (ΔP / Δr) this time,
It is determined whether the difference is within a predetermined amount. If not, return to step 16 and apply the next pressure to the probe. If it is within the predetermined amount, the load Pif is measured with a pressure gauge and transmitted to the personal computer 10 via the measuring device 8 as shown in FIG. At this time, a command for measuring the displacement is issued.

In step 22, the displacement δif measured by the displacement meter 7 is also transmitted to the personal computer 10 via the measuring device 8, and the displacement δif measured in step 15 is calculated from the displacement δif measured in step 22. The displacement amount δf at the time of the load Pif is obtained by subtraction. In step 23, the displacement δf is divided by the load Pif,
The displacement amount mm of the hole diameter per 1 kg / cm ^{2 of the} loaded load is obtained, and this value is used as the excavation evaluation in step 24, that is, as the crushing strength of the rock, and the evaluation value of the friability is obtained based on the magnitude of the excavation. indicate.

In the above, in steps 16 to 20 of the flow chart of FIG. 9, it is determined whether or not the difference between the displacement amounts is within a predetermined amount, and a point at which a transition to a straight line is detected. As shown in the figure, the load 1Kg
Since the displacement amount of the hole diameter per / cm ² is obtained, the measurement can be made at any point as long as it is a linear portion regardless of the transition point. At this time, the command of the measuring point may first indicate the measurement pressure assuming a linear portion, and may further indicate the number of times after the rate of change is stabilized. Furthermore, the determination may be made from the time when the pressure when the load is applied is stabilized.

Next, FIG. 11 shows an example in which the data measured at the same time as the experimental example (1) is used as the crushing strength of the rock in the second embodiment. FIG. 11 shows that the horizontal axis represents a load of 1 kg.
The correlation is shown by taking the displacement mm of the hole diameter per / cm ² and the work amount (m ³ / one hour H) on the vertical axis. The friability evaluation value can be obtained as in Experimental Example 1, and a suitable model can be selected. Furthermore, in the above, the computer was used to automatically display the selection of compatible models.However, the displacement was measured while applying pressure with a pressure source and a measuring instrument, and the difference between the displacements was subtracted or the pressure was measured. By dividing by the difference in the amount of displacement, the crushing strength of the rock is calculated by a computer using the method of setting the friability evaluation criteria for the upper layer of the rock,
It is possible to select a suitable model by comparing the crushing strength of the rock with a graph displaying the suitable model of the construction machine.

[0027]

As described above, according to the present invention,
In the equidistribution loading method using boring holes, the difference between the amount of displacement after hitting the hole wall and the amount of displacement corresponding to the prescribed load is calculated as the amount of hole displacement, and the hard and soft geology is determined from this value. Because the crushing strength of the bedrock is required, it can be easily measured even by a skilled worker. In addition, the correlation between the crushing strength of the rock obtained by the above method and the work amount of the excavated construction machine is obtained and stored in a personal computer, and the crushing strength of the rock at the site where the work is newly performed is measured. Since the crushing strength of the construction machine or the number of construction machines suitable for the site to be introduced can be selected based on the crushing strength or construction period, the size of the construction machine suitable for the work site and the amount of work can be easily determined from this displacement amount.
The effect that estimation can be performed in a short time is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a measuring apparatus for measuring the friability of a rock upper layer used in the present invention.

FIG. 2 is a block diagram of an apparatus for measuring the friability of the upper layer of rock used in the present invention.

FIG. 3 is a flowchart of a first embodiment of a friability evaluation standard for a rock upper layer used in the present invention.

FIG. 4 is a diagram of an embodiment showing a pattern of a load.

FIG. 5 is a diagram showing the relationship between the amount of displacement and the applied load in an in-hole loading test using an evenly distributed loading method.

FIG. 6 is a diagram showing a relationship between a displacement amount and a load in a borehole loading test of hard geology.

FIG. 7 is a diagram showing a relationship between a displacement amount and a load in a borehole loading test of soft geology.

FIG. 8 is a diagram showing measured values of a hole displacement amount δ and a work amount per hour (m ³ / hour H).

FIG. 9 is a flow chart of a second embodiment of the criterion for evaluating the friability of the upper rock layer used in the present invention.

FIG. 10 is a diagram showing a relationship between a displacement amount and a load in a hole loading test according to a second embodiment.

FIG. 11 is a diagram showing measured values of a hole diameter displacement amount per 1 Kg / cm ^{2 of} loading holes and a work amount per hour (m ³ / hour H).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pressure source 3 Probe 5 Pressure gauge 7 Displacement gauge, 8 Measuring instrument, 10 Personal computer, 50 In-hole loading test machine, 51 Rock,

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01N 3/00 E02D 1/00 E21B 47/00 EPAT (QUESTEL) JICST file (JOIS)

Claims (4)

(57) [Claims] 1. A borehole is drilled from the upper surface of a bedrock, and a probe of the boreload tester is placed in the hole to set a criterion for evaluating the friability of an upper layer of the bedrock by a bore tester using an equal pressure distribution loading method. In the method of setting the friability evaluation standard of the upper rock layer by changing the radius in the hole by loading the intermittent load on the hole peripheral wall with the probe intermittently, and by increasing the load, and measuring the change, The difference between the displacement at the point where the change in the displacement changes linearly with the change in the load and the initial displacement when the load of the extension of the straight line is zero is obtained.
A method for setting a crushing strength evaluation standard for an upper layer of a rock, wherein the crushing strength of the rock is obtained based on the magnitude of the difference. 2. A borehole is drilled from the upper surface of a rock and a probe of the hole load tester is placed in the hole to set a criterion for evaluating the friability of an upper layer of the rock by using an in-hole loading tester using an equal pressure distribution loading method. In the method of setting the friability evaluation standard of the upper rock layer by changing the radius in the hole by loading the intermittent load on the hole peripheral wall with the probe intermittently, and by increasing the load, and measuring the change, The displacement (δ) when the probe comes into contact with the peripheral wall of the hole with respect to the change in the load and the displacement (δif) and the load (Pif) when the displacement with respect to the load changes in a linear line are determined. Heavy (Pi
f) A method for setting a crushing strength evaluation standard for an upper layer of rock, wherein the crushing strength of rock is obtained by the magnitude of a difference [(δif)-(δ)] per displacement. 3. The method according to claim 1, wherein the crushing strength of the rock is determined by the magnitude of the displacement (mm) per kilogram / square centimeter of the applied load. 4. A pressure source 1 of an in-hole loading tester using an equal pressure distribution loading method, a probe 3 made of a rubber tube or the like inserted into the hole and expanding the hole, and a pressure applied to the probe 3 And a displacement gauge 7 built in the probe 3 and measuring the displacement in the hole due to the pressure applied to the probe 3, which measures the crushing strength of the rock mass. A storage device for storing compatible models of construction machines, and a signal from the pressure gauge 5 and the displacement gauge 7, the amount of deformation at a displacement point that shifts to a straight line and the amount of displacement when the load of the extension of the straight line is zero. Or the ratio to the difference between the amount of displacement of the applied load and the amount of displacement when the applied load is zero with respect to the applied load at an arbitrary point in the linear portion, and the difference or the magnitude of the ratio Determine the crushing strength of the rock mass and It comprises a computing device 9 for comparing the crushing strength and the obtained crushing strength of the rock to select several types of suitable construction machines, and a display device 10 for displaying a model so that a model can be selected from the selected several types of compatible models. Characteristic setting device for friability evaluation standard of upper rock layer.