KR100915544B1 - Penetration test apparatus for geotechnical site investigation - Google Patents

Abstract

The present invention is difficult to penetrate the sampler in the hard strata, gravel layer, soft rock, etc. due to the constraints of the diameter of the ground sampler, impact energy, etc., and solves the problem of calculating the reliable irradiation value, the cutting edge at the end And a shoe formed as an end to be inserted, the inner tube connected to the upper inner side of the shoe, the inner tube having a hollow portion for sampling, and an outer tube covering the inner tube and connected to the upper outer side of the shoe. A sampler having a structure and intruding into the ground to collect a sample; Hammer price means for providing blow energy to intrude the sampler; And a penetration measurement means for measuring the penetration amount of the sampler by the hammer price means.

Therefore, according to the present invention, it can be used for hard strata, gravel layers, soft rocks, etc., and it can not only derive the number of blows when the sampler is penetrated at a constant depth, but also simultaneously collect samples of the target ground, and is obtained through the penetration test apparatus. It has the effect of providing a large penetration test device for the ground survey that can measure energy efficiency with a value and can be used with great utilization in various grounds.

Ground survey; Penetration test; Sampler; Sampling

Description

Large Penetration Test Apparatus for Geotechnical Site Investigation

1 is a schematic use state of the large penetration test apparatus for the ground survey according to the present invention.

Fig. 2 is a sectional view showing the configuration of the sampler shown in Fig. 1;

* Description of the main parts of the drawings

10: sampler 11: shoe

12: inner tube 13: appearance

14 connector head 15 ball valve

16: air passage 20: hammer

30: penetration measurement means 40: anvil

50: load 60: automatic fall

70: cat head 71: rigid rope

72: poly

The present invention relates to a large penetration test apparatus for the ground survey. More specifically, the present invention can not only evaluate the strength of the ground at the same time as the sampling for the engineering classification of the ground, but also can be used for hard strata, gravel layers, soft rocks, etc. The present invention relates to a large penetration test apparatus for soil investigation that can classify soil using samples collected by a sampler.

In general, ground surveys are essential for the safe and economical design and construction of structures and for the maintenance, repair and safety diagnosis of existing structures.

The ground condition is used to determine the condition of the ground, the strata structure, and the bearing capacity.The obtained ground survey results are used to construct the structure to be constructed safely and economically, and to use it as basic data for maintaining and managing the structure in the future. Done.

Therefore, accurate and reliable ground survey should be carried out on the target ground, but since the types of ground are very diverse, it is impossible to apply the same ground survey technique to all grounds. In addition, various ground survey techniques have been proposed according to the characteristics of the ground, and the ground survey method and analysis method suitable for each ground characteristic should be determined.

For example, in some cases, the cone penetration test is used to investigate the ground of soft ground, but the standard penetration test for most grounds in Korea is due to the advantages of the test method and the ease of sampling. : SPT) is the most widely used. In addition, the standard penetration test for conventional ground investigation hits the top (anvil) of the rod connected to the split spoon sampler by freely dropping 63.5 kg metal hammer at a height of 75 cm. In-situ test that intrudes the sampler into the ground, measures the penetration and the number of hits of the sampler, and collects the disturbance sample (based on KS F 2307) .The number of hammer strikes required for the 30 cm penetration of the sampler is called N value. Using the N value, the hardness of the strata can be evaluated or various ground constants can be empirically calculated.

In addition, in North and South America, about 85 to 90% of the general basic design is carried out based on the standard penetration test (Bowles, 1988). In Japan and Korea, most geotechnical designs result from this test. It depends on the situation. In principle, such a test is limited to sandy soil, but in Korea, this test is also used in various kinds of soils.

However, in the standard penetration test, the sampler is difficult to penetrate in the hard strata, gravel, and soft rock due to the constraints of the sampler's diameter and the impact energy, and there are many problems in calculating the reliable N value.

In order to solve these problems, developed countries are using percussion drilling using mechanical vibration intrusion or improving existing standard penetration tests. However, the research is still in its infancy and there are no standardized standards or test methods for each country.

Therefore, the present invention has been proposed to solve the above problems, the object of the present invention is not only to the ground to which the existing standard penetration test can be applied but also to the hard strata, gravel layer, soft rock, etc. It is to provide a large penetration test apparatus for the ground survey can also be utilized.

Another object of the present invention is not only to derive the number of blows when the sampler is deeply infiltrated to the hard strata, gravel layer, soft rock, etc., but also a large penetration test apparatus for ground investigation that can simultaneously sample the ground. It is to provide.

Yet another object of the present invention is to measure the energy efficiency of the N value obtained through the penetration test device, to derive a correlation with the standard penetration test, large penetration test device for the ground investigation that can be used with great utilization in various soils It is to provide.

In order to achieve the above object, the present invention can be applied not only to the ground to which the existing standard penetration test can be applied, but also to the hard strata, gravel layer, and soft rock which cannot be applied to the existing standard penetration test. It is implemented to effectively calculate the sample and take the sample, the sampler is introduced into the ground to collect the sample, the hammer price means for providing a blow energy to inject the sampler, and the sampler intrusion amount by the hammer price means It provides a large penetration test apparatus for the ground survey including a penetration measurement means for measuring the.

And, the hammer price means is connected to the upper portion of the sampler, is connected to the lower portion of the anvil, the rod for transmitting the impact energy of the hammer applied by the anvil to the lower sampler; An anvil connected to the top of the rod, the anvil being hit by a hammer and transferring the striking energy to the rod; And a hammer automatic dropping means including a hammer and lifting and lowering the hammer to freely drop the hammer when reaching a predetermined height.

The hammer automatic dropping means may include a hammer, a hammer lift for elevating the hammer, and an automatic dropping, the rod further includes a strain gauge and an accelerometer, and the strain of the rod generated when the hammer strikes the anvil. Integrate and convert acceleration and acceleration into force and particle velocity, calculate maximum hammering energy of hammer, and measure energy efficiency transferred from potential energy of hammer to rod.

The hammer has a weight of 150 kg, and the automatic drop automatically falls when the hammer is raised to 750 mm.

In addition, the sampler has a cutting blade is formed at the end, the shoe is formed into the inlet end, connected to the upper inner side of the shoe, the inner tube formed with a hollow for sampling, and covers the inner tube, It is implemented as a large sampler of a dual structure including an appearance connected to the upper outer side.

The sampler further includes a ball valve for discharging air inside the sampler, which is a hollow portion, and an air discharge port formed at an upper portion thereof, connected to an upper portion of the inner tube and an outer portion, and connected to a hammer price means.

The inner diameter of the sampler forming the hollow portion is 63 mm, the outer diameter is 76 mm, and the length is 500 mm. The shoe is characterized in that the reinforced heat treatment.

The penetration measuring means measures and records the penetration depth of the sampler per hammer by the hammer price means with an error within 1 mm, and records the penetration depth when the sampler penetrates 300 mm. Large penetration test device.

Hereinafter, the configuration, function and effects of the preferred embodiment of the large penetration test apparatus for the ground investigation according to the present invention will be described in detail.

1 is a schematic diagram of a state of use of a large penetration test apparatus for the ground survey according to the present invention, Figure 2 is a cross-sectional view showing the configuration of the sampler shown in FIG. As shown in the figure, the large penetration test apparatus 100 for the ground survey according to the invention includes a sampler 10, a hammer price means, a penetration measurement means 20.

The sampler 10 is introduced into the ground to collect a sample, and as shown in FIG. 2, the shoe 11, the inner tube 12, the exterior 13, and the ball valve 15 of the connector head 14. And an air outlet 16. The shoe 11 is formed by the cutting edge is formed into the tip, the end to be penetrated. In addition, the shoe is preferably subjected to a reinforcement heat treatment for sampling of the hard strata.

In addition, the inner tube 12 is connected to the upper inner side of the shoe 11, the hollow portion for sampling is formed. In addition, the exterior 13 covers the inner tube 12 and is connected to the upper outer side of the shoe 11.

In addition, the shoe and the inner tube according to the present invention can be integrally formed unlike the above embodiment, the technical details of the present invention can be implemented in a variety of structures in a satisfying range.

The sampler 10 according to the present invention is not only more robust as it is formed in a dual structure according to internal medicine and appearance, and can be implemented for large penetration. In addition, the connector head 14 is connected to the upper portion of the inner tube and the exterior, and is connected to the hammer price means. The inner diameter of the sampler 10 is 63 mm, the outer diameter is 76 mm, and the length is preferably 500 mm.

And, as the sample is pushed into the sampler, a ball valve 15 and an air outlet 16 are formed on the upper part of the sampler 10 to discharge the air inside the sampler, and the connector head 14 is the sampler. 10 and the guide rod 50 of the hammer price means.

Next, the hammer price means for supplying the impact energy to penetrate the sampler 10, and includes a rod 50, anvil 40, and the hammer automatic dropping means.

The rod 50 is connected to the upper part of the sampler, and is connected to the lower part of the anvil to transfer the hammering energy of the hammer applied by the anvil to the lower sampler, and the anvil 40 to the upper part of the rod 50. It is connected, hit by the hammer 20, to withstand the impact of the hammer and transmit the hammering energy of the hammer to the lower rod (50).

In addition, the hammer automatic dropping means for lifting and lowering the hammer 20 and freely dropping the hammer when reaching a predetermined height, the hammer 20 and the hammer lifters 70, 71 and 72 for lifting and lowering the hammer 20. , Automatic dropping (60) and the guide rod (80).

The hammer 20 preferably has a weight of about 150kg to be implemented in a large penetration test apparatus. The hammer lift may be implemented in various ways using a cat head 70, a rigid rope 71, a poly 72, and the like. In addition, the guide rod 80 is for guiding the hammer to hit the anvil accurately, is connected to the upper portion of the anvil (40). And, the automatic dropping 60 is preferably set to fall automatically when the hammer is raised to 750mm, it can be easily implemented by those skilled in the art of the present invention, all of the scope of the present invention Im obvious.

The penetration measuring means 30 is for measuring the penetration amount of the sampler by the hammer price means. When the anvil 40 is hit by the hammer 20, the penetration depth of the sampler 10 is measured for each hit. It consists of automatic measuring equipment that measures and records with error within 1mm and records penetration depth when sampler penetrates 300mm.

As such, a large penetration test apparatus for the ground survey according to the present invention is made, and one embodiment of the ground survey using the penetration test apparatus 100 will be described in detail below.

First, use the boring equipment to excavate the ground to the desired depth, and install the casing so that the empty wall does not collapse. Then, the sampler 10 connected to the rod 50 is located on the excavation bottom surface, the hammer 20 and the hammer lifter are positioned on the upper part of the anvil 40, and the penetration depth measuring means is installed.

Then, when hitting the anvil 40 using a hammer lift, the sample 11 enters the hollow portion of the sampler while the shoe 11 of the lower portion of the sampler 10 is introduced into the ground. At this time, the air inside the sampler is discharged to the outside of the sampler 10 through the ball valve 15 and the air passage (16). In addition, the sampler consisting of a double tube of the inner tube 12 and the outer tube 13 formed in two in the longitudinal direction serves to prevent the groundwater from flowing into the sampler when the sampler is introduced to the ground water level. In an area without groundwater, a single tube type sampler using only the vertically divided facade 13 may be used.

Next, when the sampler 10 is introduced to the depth of 300mm according to the hammer hit, the number of hits at that time is automatically recorded by the penetration measurement means 30, stops the hammer hit and pulls out the sampler to the ground.

The hit number N of hammers irradiated in this way is used to determine the characteristics of the ground, and the collected sample can be used to determine the physical properties of the ground through the determination of soil type in the laboratory and various related experiments.

The N value calculated by the penetration test is different from the N value calculated by the standard penetration test, but when the correlation is derived from the N value of the standard penetration test for the same ground, the characteristics of the target ground are determined using only the results of the large penetration test. It becomes possible.

Further, a full bridge type strain gauge and an accelerometer are attached to the rod 50 under the anvil 40, and the strain and acceleration of the rod 50 generated when the hammer 20 hits the anvil. Is converted into force and particle velocity, integrated, and the maximum impact energy of the hammer 20 is calculated to measure the energy efficiency transferred from the potential energy of the hammer to the rod, regardless of the type of large penetration test equipment. Can be used to improve the usability.

The present invention described above is not limited to the above-described embodiments and drawings, and various permutations, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be apparent to those who have

As described above, according to the present invention can be applied not only to the ground to which the existing standard penetration test can be applied, but also to the hard strata, gravel layer, soft rock, etc., to which the existing standard penetration test cannot be applied, and the number of blows when the sampler is penetrated to a certain depth. In addition, it has the effect of providing a large penetration test apparatus for the ground survey, which can extract samples of the target ground at the same time, and the N value obtained through the penetration test apparatus measures the energy efficiency and standard penetration It has the effect of providing a large penetration test device for the ground survey that can be used with great utilization in various grounds by deriving the correlation with the test.

Claims (10)

A cutting blade is formed at the end, and the shoe is formed into the inlet end, and connected to the upper inner side of the shoe, the inner tube formed with a hollow portion for sampling, the inner tube and connected to the upper outer side of the shoe A ball valve and an air discharge port are formed on the upper part of the outer part, including a connector head connected to the upper part of the inner tube and the outer part, and connected to a hammer price means, and discharging the air inside the hollow part. A sampler to collect; A rod connected to the upper part of the sampler and connected to the lower part of the anvil to transfer the hammering energy of the hammer applied by the anvil to the lower sampler, and a rod connected to the upper part of the rod and hit by the hammer and loaded with the hitting energy. A hammer price means including an anvil delivered to the hammer, a hammer automatic falling means including a hammer and lifting and lowering the hammer to freely drop the hammer when reaching a predetermined height, the hammer price means for injecting the sampler; And a penetration measuring means for measuring the penetration amount of the sampler by the hammer price means. The hammer has a weight of 150kg, and the hammer automatic dropping means is to lift the hammer and freely drop the hammer when the hammer reaches 750mm, The sampler has an inner diameter of 63 mm, an outer diameter of 76 mm, a length of 500 mm, and a hollow portion. The penetration measuring means is an automatic measuring device for measuring and recording the penetration depth of each sampler by the hammer price means with an error within 1 mm, and recording the penetration depth when the sampler penetrates 300 mm. Large penetration test device for ground survey. delete The method of claim 1, The hammer automatic dropping means A hammer, a hammer lift for elevating the hammer, and an automatic falling Large penetration test device for ground survey. The method of claim 1, The rod is It further includes a strain gauge and an accelerometer, converts and integrates the strain and acceleration of the rod generated when the hammer hits the anvil into force and particle velocity, and calculates the maximum impact energy of the hammer to the rod from the potential energy of the hammer. To measure the delivered energy efficiency Large penetration test device for ground survey. delete delete delete delete The method of claim 1, The shoe is Reinforcing heat treatment Large penetration test device for ground survey. delete

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