JPH07150882A - Cone loading mechanism for rotary intrusion type ground strength investigating device - Google Patents

Abstract

PURPOSE:To prevent lowering of precision on strength information of a soft ground when the strength of a soft ground is investigated by a rotary intrusion type ground strength investigating device. CONSTITUTION:A cavity part 6 is formed in an excavation bit body 3 of a measuring rod 2 and an intrusion resistance detecting cone 9 having a flange 10 is balanced with an intrusion resistance detecting cone 9 moved backward by intrusion resistance against a press force generated by a coil spring 11. The stroke of the intrusion resistance detecting cone 9 is reliably detected by a differential transformer 19 of the stroke measuring instrument of a sensor needle 23 formed integrally with the intrusion resistance detecting cone 9 to measure a ground strength. The forward and backward movement stroke of a forward and backward movement sensor needle 23 of the intrusion resistance detecting cone 9 in a soft ground is reliably detected by the differential transformer 19. The detecting data is numerically expressed together with parameters, such as the rotation speed, the excavation speed, the bit load, and rotation torque of an excavation bit to process the numerical value, and strength information of the soft ground is further reliably provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The disclosed technology belongs to the technical field of the structure of a test apparatus for investigation of the strength of the ground.

[0002]

2. Description of the Related Art Effective use of land has been a very important issue for a long time in Japan, where the land is narrow and there are many mountainous forest areas. Therefore, various technologies related to ground research, development, Improvements have been made. For example, it is important to investigate the ground strength when constructing various facilities, and the invention is disclosed in JP-A-63-142114 and JP-A-2-308.
Inventions and the like have been devised.

Thus, the so-called rotary penetration type ground strength investigation technique is known as disclosed in Japanese Patent Laid-Open No. 63-142114.

[0004]

The target ground is usually soft ground to soft rock in rotary intrusion sounding, but since it has a sensor for soft rock with a maximum strength of about 200 kgf / cm ² , it is weak. There is a drawback in that when measuring the same muddy ground with the same sensor, the accuracy falls from the range of the error.

Although cone penetration is a soil test method that is often used for soft ground, when the ground strength increases, there is a problem that penetration is difficult and the range of use is limited.

[0006]

An object of the invention of this application is to solve the problems relating to the ground strength survey technology based on the above-mentioned prior art, and to improve the accuracy of a rotary penetration type ground strength survey device excavated by a bit for soft ground. In order to improve, the cone loading mechanism is attached so that the measurement accuracy of the ground strength can be sufficiently increased, it is possible to make a sufficient economical match, and it is easy to handle and the durability is also sufficiently improved. Thus, it is intended to provide a cone loading mechanism of an excellent rotary penetration type ground strength survey device which is beneficial to the field of measurement technology application in the construction industry.

[0007]

In order to solve the above-mentioned problems, the structure of the invention of this application, which has been made in line with the above-mentioned object, is based on the above-mentioned object, when the strength condition of the target ground is investigated. , The measuring rod of the rotary penetration type ground strength survey device is installed at the tip of the boring rod.
In addition, a drilling water supply passage is provided inside from the base end to the tip, and a cone for detecting penetration resistance is provided so as to project from the drill bit, and a predetermined drilling static pressure and rotational force are applied to the boring rod. While giving and drilling water, the ground is drilled, the drilling water assists the drilling, contributes to the cooling and slime-up of the drill bit, and the cone is applied to the soft ground. Depending on the strength of the ground, the projecting amount is automatically responded to by the ammunition machine and changes, and the displacement is detected by a sensor needle integrally provided on the top of the cone with a differential transformer or encoder. Alternatively, it moves back and forth with respect to a measuring device such as a load cell with a spring, and the detected amount of that stroke is used as strength data of the ground, and is stored in a data memory and appropriately posted after the excavation is completed, or a lead wire, or , Transmitted via wireless means, etc., and processed along with the data of other measurement items by predetermined data processing on the ground, therefore, the cone slides according to the strength of the continuous formation of the ground, and the ground It is possible to reliably collect the above-mentioned strength information in the ground that cannot be directly measured from the ground, and when the ground strength of rock etc. is large, the ammunition is compressed and the cone moves its stroke. It is fixed at the end,
Since the periphery is excavated by the excavation bit, the cone can make static penetration.

[0008]

An embodiment of the invention of this application will be described below with reference to the drawings (FIG. 1 only).

Reference numeral 1 shows a main part of a cone loading mechanism of the rotary penetration type ground strength survey device of the invention of this application.
The boring rod is formed to have a predetermined length through a threaded joint of a unit rod, and is provided at a predetermined portion of the tip of a blade die 4 fixedly fixed to the drill bit body 3 at the tip of the measuring rod 2 at the tip thereof. As in the embodiment, a predetermined number of drilling bits 5, 5 ...
A cavity 6 having a bottom is formed inside, and a plug body 7 which is screwed to the drill bit body 3 and whose set height can be freely adjusted is screwed on the upper portion thereof. Further, a needle-shaped penetration resistance detection cone 9 is vertically inserted into the bottom of the drill bit body 3 through packings 8 and 8 ', and is arranged in a protruding manner with respect to the blade mold 4, and the inside of the cavity 6 is provided. At this point, a coil spring 11 as an ammunition having a predetermined spring constant is inserted between the flange 10 and the plug 7 which are integral with the penetration resistance detection cone 9, and the penetration resistance detection cone 9 is projected to the ground in a predetermined manner. In a state where the penetration resistance detecting cone 9 is retracted (raised) by the reaction force from the ground, the coil spring 11 resists this, and the plug body 7 is screwed into the excavation bit body 3 when pre-installed. By adjusting the amount, Is adapted can be adjusted repression biasing force against penetration resistance detection cone 9-yl spring 11.

A measuring rod main body 12 is joined to the upper part of the drill bit main body 3 via a screw thread so that the measuring rod main body 12 can be freely connected and disconnected, and another measuring rod main body 12 is connected between the measuring rod main body 12 and the plug 7. A cavity portion 13 is formed, and a measuring rod outer tube 15 is disposed on a side portion of the measuring rod body 12 via an O-ring 14, and also an O-ring 1 is provided.
A measurement rod inner pipe 17 is screwed and connected via 6, and a drilling water supply passage 1 is provided between the measurement rod inner and outer pipes 15 and 17.
8 is formed and is connected in communication with the drilling water supply passage 18 ′ in the measuring rod body 12, and the drilling water supply passage 18 ′ is a drilling hole formed in the drill bit body 3 and the blade die 4. The water supply passage 18 ″ is connected to the water supply passage 18 ″ through the cavity 13 to connect the drill bit 5, the blade mold 4, and the measuring rod body 12.
It is designed to be cooled and kept in a constant temperature state at all times.

A differential transformer, an encoder, or a stroke measuring instrument 19 such as a load cell with a spring is stored in advance inside the measuring rod body 12 and set therein. 12
It is supported by a cap 21 that is screwed in through O-rings 20, 20.

A sensor needle 23, which is integrally provided by inserting the cavity 13 into the casing 22 of the stroke measuring instrument 19 and pressing the tip of the tip into the upper portion of the penetration resistance detecting cone 9, is freely movable. Has been inserted into the
Further, the lead wire 24 from the stroke measuring device 19 is electrically connected to a predetermined measuring device through the atmospheric chambers 25 and 26 inside the measuring rod main body 12 in the atmospheric pressure state.

Therefore, the stroke measuring instrument 19 is exposed to the drilling water of the cavity portion 13 at the lower portion thereof, and the inside 22 of the casing thereof is communicated with the cavity portion 13, so that the stroke measuring instrument 19 flows through. It is cooled by drilling water and kept in a constant temperature state at all times so that the temperature change of the measurement data of the strength of the ground concerned does not occur due to the amount of vertical movement of the sensor needle 23 by a differential transformer, an encoder, a load cell, or the like. There is.

In addition, in a ground portion (not shown) above the measuring rod 2, a measuring device (not shown) for the excavation bit 5 of the measuring rod 2 is provided in the same manner as in the conventional mode.

In this way, the measurement of the bit load, the bit rotation torque, the drilling water pressure (for correction) and the measurement of the rotation speed and the excavation speed on the ground are performed in the measuring rod 2 as in the conventional manner. Then, the stroke of the penetration resistance detection cone 9 is detected to improve the accuracy of strength measurement.

In the above structure, when the strength of the target ground is to be investigated, the measuring rod 2 is drilled by a boring machine (not shown) on the ground at a predetermined rotation speed and a digging load. , Drilling water supply passage 1
Drilling water is supplied to 8, 18 ', 18''to assist the excavation by the excavation bit 5, and the slime generated by the excavation rises to the ground from between the outer peripheral surface of the measuring rod 2 and the drilling wall. It is processed as prescribed.

The resistance caused by drilling the soft ground acts as a stress on the penetration resistance detecting cone 9 facing the blade die 4 of the excavating bit body 3 of the measuring rod 2. Therefore, the penetration resistance detecting cone 9 is A coil spring 11 as an ammunition is compressed between the stopper 7 and the flange 7 via its flange 10, and its forward / backward stroke moves up and down inside the inside 22 of the stroke measuring instrument 19 of the sensor needle 23, thereby providing a differential transformer, an encoder and a load cell. Stroke measuring instrument 1
9 electrically detects the stroke and inputs it to the data storage device or the data transmission device via the lead wire 24.

Thereafter, the data is transcribed to a predetermined measuring device built in a computer (not shown) on the ground, and parameters such as rotation speed, excavation speed, bit load, and rotation torque with respect to the measuring rod 2 and the detection resistance by the penetration resistance detection cone 9 are detected. The strength data of the ground is collected according to the value.

In the process, the drilling water cools the excavation bit 5 and the blade type 4 of the excavation bit main body 3 to accurately measure the ground strength in the soft ground.

Therefore, in measuring the strength, the penetration resistance detecting cone 9 is balanced with the strength of the ground by the coil spring 11 of the ammunition, and the penetration measuring cone 19 of the sensor needle 23, that is, the stroke measuring device 19 is used.
It is possible to collect the ground strength information in the strata accurately by changing the advancing / retreating stroke with respect to each stratum steplessly.

In this case, since the penetration resistance detecting cone 9, that is, the sensor needle 23 also moves up and down delicately even in the soft ground, the strength information for the soft ground can be obtained accurately and in detail. You can

When it is desired to previously adjust the up-and-down movement stroke of the penetration resistance detection cone 9 by designing, by changing the screwing amount of the plug body 7 at the time of assembling the measuring rod 2 at the time of boring. The pressing force of the coil spring 11 against the penetration resistance detection cone 9 can be adjusted as desired.

Since the penetration resistance is large in the drilling of the ground having a high ground strength, the penetration resistance detecting cone 9 moves up and down to the full stroke against the spring 11, and the excavation bits 5, 5 are removed. The excavation is performed by ... And, for example, the strength measurement is performed in the same manner as in the conventional mode by the technique disclosed in JP-A-63-142114.

The slime cavities 6 and 1 during drilling
The packing 8 and 8'can prevent the intrusion of the slime 3 into the hole 3, and the O-ring 14 can surely prevent the intrusion of slime or the like into the drilling water supply passage 18.

Then, for the stroke measuring device 19,
Further, the penetration of the drilling water into the atmosphere chambers 25 and 26 inside the measuring rod body 12 and the propagation of the pressure are prevented by the O-rings 16 and 20.
Blocked by.

Of course, the embodiment of the invention of this application is not limited to the above-mentioned embodiment. For example, instead of a coil spring, an ammunition machine made of rubber or a gas damper can be used. Various modes can be adopted.

In addition to the differential transformer, the stroke measuring device can also employ electrical detecting means such as an encoder and a slide resistor, and appropriate mechanical detecting means such as a load cell equipped with a spring. is there.

As a design change, for example, a sensor needle may be provided with a double speed mechanism to enhance the sensitivity.

In this way, the penetration resistance detection cone is made to project into the ground during drilling by the bullet, and the stroke of the penetration resistance detection cone pushed back by the penetration resistance reaction force of the ground can be measured. Therefore, the strength of the ground can be reliably measured.

In particular, not only when the ground is a soft ground, but also when the ground is a ground having a wide strength distribution from the soft ground to the soft rock, the strength data for the soft ground is measured with sufficiently high accuracy. You can

[0031]

As described above, according to the invention of this application, the device for inspecting the strength of the ground, which is indispensable prior to the ground improvement and the use of the ground, is the rotary penetration sounding test system of the rotary penetration system. When measuring the rotational speed, excavation speed, bit load, rotational torque, etc. of the drilling bit at the tip of the measuring rod, the parameter of the data is numerically processed and the stroke corresponding to the penetration resistance of the cone is measured. As a result, an excellent effect is obtained that reliable intensity information can be obtained.

Therefore, there is an effect that the accuracy of measurement of soft ground strength by the rotary penetration type ground strength survey device can be remarkably improved.

Moreover, since the cone loading mechanism provided on the measuring rod to be used has a simple mechanical structure, initial assembly is easy, and there is almost no maintenance or inspection for repeated use, and durability is good. As long as that is the case, not only the initial cost but also the running cost and the maintenance cost are low, and there is an effect that it is economically well worth it.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the invention of this application.

[Explanation of symbols]

 2 Measuring rod 9 Penetration resistance detection cone 1 Cone loading mechanism 3 Excavation bit body 11 Ammunition machine (spring) 23 Sensor needle 19 Stroke measuring instrument 18, 18 ', 18' 'Drilling water supply passage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000151368 Tokyo Soil Research Co., Ltd. 2-11-16 Higashigaoka, Meguro-ku, Tokyo (71) Applicant 390036504 8-14-14 Ginza, Chuo-ku, Tokyo No. (71) Applicant 590002482 1-19-11 Kyobashi, Chuo-ku, Tokyo (71) Applicant 593040461 Toho Underground Machinery Co., Ltd. 633, Kazutsukikuma, Hakata-ku, Fukuoka-shi, Fukuoka (72) Invention Person Shohei Senda 3-10-10 Matsuba, Ryugasaki City, Ibaraki Prefecture (72) Inventor Seiichi Tanaka 2-2 Nishizawa, Tsukuba City, Ibaraki Prefecture Rotary Research Institute of Civil Engineering Research Center (72) Inventor Takao Yokohata Fukuoka Prefecture 633 Toho Underground Machinery Co., Ltd. for Kamitsukikuma, Hakata-ku, Fukuoka

Claims (3)

[Claims] 1. A cone loading mechanism for a rotary penetration type ground strength survey device, wherein a tip of a boring rod has a measuring rod for measuring excavation resistance, and a penetration resistance detecting cone is provided inside the boring rod so as to project from the excavation bit. A penetration resistance cone is supported at the center of the tip of the excavation bit body through an ammunition so as to be able to move back and forth according to the ground strength, and the penetration resistance detection cone is installed opposite to the stroke measuring device axially mounted on the measuring rod. The cone loading mechanism of the rotary penetration type ground strength investigation and testing device. 2. A drilling water supply passage provided in the measuring rod communicates with a cavity formed between the stroke measuring instrument and the penetration resistance detecting cone in the middle thereof. The cone loading mechanism of the rotary penetration type ground strength survey device according to claim 1. 3. The cone of the rotary penetration type ground strength survey device according to claim 1, wherein the stroke measuring device is a load cell through a differential transformer, an encoder, or a spring. Loading mechanism.