JPH0258404B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic penetration testing machine that easily investigates the soil bearing capacity of a building when installing a foundation, for example in housing construction work.

In residential construction work, the bearing capacity and soil quality of the construction site are investigated when installing the foundation to ensure that the house can be safely constructed and maintained. In this survey, we learn the hardness and softness of the soil and the degree of compaction, and then set the foundation.

Conventionally, a dynamic conical penetration (hereinafter referred to as the PWRI type) testing machine has been used as a soil quality investigation method. This PWRI-type testing machine was devised for the purpose of measuring the ground support of earthen walls on roads. A penetrating rod is manually operated to penetrate into the ground under investigation, and the soil quality is investigated based on the degree of penetration. This PWRI testing machine uses only one rod with a length of 1 m, so it was not possible to investigate deeper than 1 m.

However, in order to determine the bearing capacity of a building, it is necessary to collect data from a deeper location, for example from 2m to approximately 10m below the ground surface. In addition, it is not possible to say that a sufficient soil bearing capacity has been investigated unless several types of cones are penetrated not just at one location but at several locations to comprehensively investigate the hardness and softness of the soil, the degree of compaction, and the presence or absence of rocks.

Therefore, it is insufficient to investigate the soil bearing capacity of buildings using conventional PWRI testing machines.

In addition, since this PWRI testing machine is operated manually, it lacks accuracy, and the required number of personnel must be secured, which poses difficulties in terms of danger, fatigue, etc.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide an automatic penetration testing machine that focuses on measuring soil bearing capacity for foundation design of small-scale buildings such as houses. be.

That is, the automatic penetration testing machine of the present invention includes: a drive device that winds a wire and opens it at regular intervals; a driving device connected to the wire;
The rod penetrated into the ground by the driving device is sandwiched between a guide roll and a foil that are connected to each other by a support plate, and these are held by a foil stand, so that the rod is covered with foil. and an automatic recording device that records the degree of penetration of the rod by transmitting the rotation of the foil to the recording device via a universal joint.

Hereinafter, details of the present invention will be explained with reference to the drawings showing one embodiment thereof.

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is an enlarged perspective view of the inside of the storage box, FIG. 3 is a perspective view of the automatic recording device, and FIG. 4 is a front view showing an example of the cone.

In the figure, reference numeral 1 denotes a rod that is driven into the ground, and this rod 1 is equipped with a wire winding drum 2 and a drive equipped with a cam 4 that opens the wire 3 wound on the wire winding drum 2 at regular intervals. It is driven into the ground using the device 5 and the driving device. The degree of penetration of the rod 1 is recorded by an automatic recording device 8 via a foil 6 placed in contact with the rod 1. 7 is a cone with a slightly thick diameter that is loaded onto the tip of the rod and driven into the ground.

This driving device 5 and automatic recording device 8 will be explained with reference to FIGS. 2 and 3.

The cam 4 of the drive device 5 is driven by a power mechanism 9 such as a motor via a chain 10 to operate a driving device connected to the wire 3 and cause the rod 1 to penetrate.

Further, the automatic recording device 8 is composed of a universal joint 11 that transmits the rotation of the foil 6 installed in contact with the lower end of the rod 1 in the penetration direction, and a recording device operated by the universal joint 11. The recording device is recording paper 1
2, drums 15, 15', and a writing instrument 13. The universal joint 11 further rotates the winding frame feed shaft 14 via the universal joint 11'. The winding frame feed shaft 14 is connected to the drum 1 by a chain.
Rotate 5, 15'. When the rod 1 penetrates, the wheel 6 rotates, the winding frame feed shaft 14 rotates via the universal joints 11 and 11', and the drum 15,
15' rotates to move the recording paper 12 wound around it. When the recording paper 12 moves, a writing instrument 13 such as a ballpoint pen, which is in contact with the recording paper 12, records a line corresponding to the movement on the recording paper 12. Further, as shown in FIG. 6, the recording paper 12 is marked with a dividing line 38 corresponding to each stroke of the rod 1 driven by the driving device.
It is now possible to enter the following information. When the separation line roll 13' shown in FIG. 3 passes over the protrusion of the wire winding drum 2, the writing instrument 13 moves perpendicularly to the direction of movement of the recording paper and draws the separation line 38. Also,
In order to draw a long dividing line 39 every five times the rod 1 is driven, a line drawing gear 16 is attached to the shaft of the cam 4, as shown in FIG. By the pressing arm of this drawing gear 16, the writing instrument 3 is drawn every 5 times.
, and draw a long dividing line 39.

That is, as shown in FIG. 6, lines are drawn by moving the recording paper 12 according to the rate of penetration of the rod 1, and a vertical dividing line 38 is drawn with each blow.
A long dividing line 39 is recorded on the recording paper 12 every five hits.

Next, the driving device is the pillar 17 and the guide rod 1.
9, a hammer 20, and a knotting head 21. In the figure, a support 17 is erected in a storage box 22 that encloses a drive device 5 and an automatic recording device 8. A metal fitting 23 for attaching a tiger rope is loaded at the tip of this support 17, and a tiger rope 24 is stretched from this metal fitting 23 on three or four sides to fix the support 17. A pair of upper and lower guide arms 25 and 26 are fixed to this support column 17 so as to project outward. A rod 1 with a cone 7 loaded at its tip is vertically inserted into and held by the lower guide arm 25, and a guide rod 19 having a knotting head 21 fixedly attached to its lower end is inserted and held by the upper guide arm 26. A knotting head 21 is mounted above the rod 1. This guide rod 19
A vertically movable hammer 20 is fitted onto the knotting head 21 of the hammer. A guide roll 27 is fixedly installed on the upper part of the column 17, and this guide roll 2
A wire 3 is suspended, one end of which is connected to the hammer 20 and the other end of which is connected to the wire winding drum 2 via a wire 7.

Next, a foil 6 connected to the universal joint 11 is brought into contact near the penetration portion of the rod 1 so as to sandwich the rod 1 between it and a guide roll 28. That is, this foil 6 is constructed by sandwiching the rod 1 between a support plate 29 together with a guide roll 28, and suspending this from a foil stand 31 by a chain 30. In this way, the foil 6 is held by the foil stand 31 so that the recording device 8 does not receive the impact directly when the foil 6 penetrates the rod 1. Also,
The universal joints 11, 11' also prevent the impact when the rod 1 is penetrated from being transmitted directly to the recording device.

Reference numeral 32 denotes a limit stopper, which is disposed in contact with the foil 6. When the knocking head 21 is lowered due to the vertical movement of the hammer 20, the detecting rod 33 of the limit stopper 32 causes the knocking head 2 to drop.
When the rod 1 makes contact, an electric signal is output to the drive section of the penetrating device 5 to stop the drive, and a new rod 1 is added to continue the penetrating operation.

Reference numeral 34 is a level for the storage box 22, 35 is a counter, 36 is an outlet for connecting to a power source, and 37 is a remote control switch.

Next, the shape of the cone 7 will be explained with reference to FIG.

The cone 7 is attached to the tip of the rod 1 and penetrates into the ground, and it has two types of shapes: one is a conical shape with a tip angle of 60° and an outer diameter of 3.0 cm ( A type cone) and the other have a tip angle.
There are two types: a conical shape with an acute angle of 30 degrees and an outer diameter of 3.0 cm (B-shaped cone).

Next, the driving rod 1 that holds the cone 7 is an iron rod with an outer diameter of 19 mm and has a scale of 1 mm engraved on it so that it can be added and disassembled every 1 m.

The hammer 20 that moves up and down the guide rod 19 weighs 8.9 kg and falls about 50 cm between the upper guide arm 26 and the knotting head 21.

Next, a method of investigation using the automatic penetration testing machine of the present invention will be explained.

The automatic penetration tester of the present invention is installed on the land to be measured, that is, the support 17 is erected, the tie rope 24 is stretched, and the support 17 and the storage box 22 are fixed. The investigation method is to press the button on the remote control switch 37 from a distance and input power to the drive device 5 in the storage box, and the cam 4 will operate to release the wire 3, which will weigh 8.9 kg.
A hammer 20 is allowed to fall freely from a height of 50 cm, and a rod with a diameter of 19 mm is penetrated into the ground. The number of strikes is set at 30 per minute. The striking method is to wind up the hammer 20 using the cam 4 and the wire winding drum 2, allow it to fall freely and strike the knocking head 21, and repeat this operation.

Next, the penetration degree (cone tip resistance value) of the rod 1 is automatically recorded on the recording paper 12 by the automatic recording device 8. This recording method is such that the foil 6 rotates due to the penetration of the driving rod 1, and this rotation causes the universal joint 1 to rotate.
1, 11' to the winding frame feed shaft 14, and the recording paper 12 is wound around the drums 15, 15'.
is sent with a length reduced to exactly 1/4 of the penetration of rod 1. At that time, using the writing instrument 13, the recording paper 1
Recorded in 2. As shown in FIG. 6, a dividing line 38 for each blow and a long dividing line 39 for every five blows are drawn on the recording paper 12 to make it easy to read the degree of penetration depending on the blow. The total number of hits is displayed on the counter 35. By performing the above operations, the recorded data can be analyzed and the Ns value used to determine the bearing capacity of the soil can be measured. The Ns value is obtained as a result as shown in FIG.

Note that the Ns value is calculated using the following formula.

Ns value = (100/penetration amount) x number of strikes Next, load a different type of cone into driving rod 1, move it slightly, and conduct an investigation using the same method. The results are also shown in FIG. 5 using Ns values.
In the figure, symbol A indicates an A-type cone, and B indicates a B-type cone. In the case of Figure 5, it can be seen that there is a soft stratum at a penetration depth of 100 cm, and a slightly harder stratum at a depth of 600 to 700 cm.

The nature of the land layer can be accurately determined based on the difference in the degree of penetration between the two cones, the A-type cone and the B-type cone.

As explained above, since the penetration testing machine of the present invention conducts the investigation automatically, unlike manual testing machines, it does not require long periods of time due to personnel shifts and breaks, and it is possible to check the soil properties during the investigation. There is no change in accuracy due to changes in

Further, the present invention has the following effects.

(1) Since the rod is opened at regular intervals by the drive device, the rod penetrates at a constant speed with a constant impact energy, and an ideal penetration resistance value with high accuracy can be obtained.

(2) The rod to be penetrated is sandwiched between a guide roll and a foil that are connected to each other by a support plate, and these are held by a foil stand, so that the foil is brought into contact with the rod and the rotation of this foil is recorded via a universal joint. Since the impact is transmitted to the device, the impact caused by the rod's penetration is prevented from being directly transmitted to the recording device, and the degree of rod penetration can be accurately recorded. Also, because it uses a universal joint,
Measurement and recording becomes easy without being restricted by the positional relationship between the rod and foil and the recording device. This is particularly effective at construction sites, where measurement locations are often restricted due to heavy materials.

(3) Since the goal is to measure up to 10 meters underground,
A depth Ns value graph can be drawn to clearly judge the soil consolidation density and the depth of the supporting layer between them.

(4) Measurement time can be shortened and labor can be saved.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is an enlarged perspective view of the storage box, Figure 3 is a perspective view of the automatic recording device, Figure 4 is a front view of the cone, Figure 5 is a graph showing measurement results, and Figure 6 is a plan view showing an example of recording paper. It is a diagram. 1... Rod, 2... Wire winding drum,
3... Wire, 4... Cam, 5... Drive device,
6...Foil, 7...Cone, 8...Automatic recording device, 9...Motor, 10...Chain, 11,1
1'... Universal joint, 12... Recording paper, 13... Writing instrument, 17... Support, 19... Guide rod, 2
0... Hammer, 21... Knocking head, 2
2...Storage box, 23...Tiger rope attachment fittings,
24... Tiger rope, 25, 26... Guide arm, 27,
28... Guide roll, 29... Support plate, 31...
...Foil stand.

Claims (1)

[Scope of Claims] 1. A drive device that winds up a wire and opens it at regular intervals, a driving device connected to the wire, a rod that is penetrated into the ground by the driving device, and a rod that penetrates into the ground by the driving device. The rod to be rotated is sandwiched between a guide roll and a foil that are connected to each other by a support plate, and these are held by a foil stand, so that the foil is brought into contact with the rod, and the rotation of this foil is transmitted to the recording device via a universal joint. and an automatic recording device for recording the degree of penetration of the rod. 2. Claim 1, wherein the drive device is composed of a wire winding drum and a cam.
Automatic penetration testing machine as described in section. 3. The automatic penetration testing machine according to any one of claims 1 to 2, characterized in that the driving device comprises a support, a guide rod, a hammer, and a knotting head. 4. The automatic penetration testing machine according to any one of claims 1 to 3, wherein the rod has a slightly thick cone at its tip. 5. The automatic penetration testing machine according to any one of claims 1 to 4, characterized in that it is composed of two types of cones having different diameters and tip angles.