Vibro-hammer pile driver equipped with pile construction support system

Abstract

To provide a vibrohammer pile driver equipped with a pile construction support system that determines whether a pile a has reached a predetermined support layer.SOLUTION: The present invention has a leader 5 equipped with a vibrohammer 7 that applies vibration to a pile (a), a pushing hydraulic cylinder 12 that pushes the pile (a) into the ground via the leader 5, and a pile construction support system 3 that provides an indicator necessary to determine whether the tip of the pile (a) has reached a specified support layer. The pile construction support system 3 has a data input unit 24 that receives data including the hydraulic pressure of a pushing hydraulic cylinder 12, the eccentricity of an eccentric weight 22 of the vibrohammer 7, and the penetration depth of the pile (a), a calculation unit 25 calculates the pushing force and pushing speed of the pushing hydraulic cylinder 12 and the excitation force of the vibrohammer 7 from the data taken into the data input unit 24, and a display unit 26 that displays the correlation between the pushing force, pushing speed, and excitation force and the N value investigated in advance.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vibro hammer pile driver equipped with a pile construction support system, which can easily and surely penetrate a prefabricated pile such as a steel pile to a predetermined support layer set by the N value, and can accurately determine whether the tip of the prefabricated pile has reached the predetermined support layer.

Background Art

[0002] When constructing a prefabricated pile such as a steel pile, it is necessary to investigate in advance the depth where the support layer exists by the N value and make the tip of the pile reach the predetermined support layer set by the N value. The constructor is obliged to confirm that the tip of the pile has reached the predetermined support layer set by the N value during construction.

[0003] Here, the N value refers to a value indicated by the number of blows required to penetrate a sampler, which is a reference pile, into the ground by a predetermined depth using a predetermined striking instrument.

[0004] For example, when constructing a foundation pile such as a steel pile by the vibro hammer method, it is possible to determine that the tip of the foundation pile has reached the support layer by pressing the foundation pile to the depth where the support layer indicated by the N value exists.

[0005] Also, for example, Patent Document 1 discloses an invention of a vibro hammer construction machine that installs a construction object such as a pile in the ground by forcibly applying vibration to the construction object such as a pile using a vibro hammer, and includes a construction support information calculation device that can accurately calculate an index indicating the depth of the support layer for each construction object such as a pile.

[0006] In simple terms, the system includes an acquisition unit that acquires information from the vibro-hammer, including values ​​indicating at least the excitation force and number of blows of the vibro-hammer and the penetration depth of the object to be constructed; a calculation unit that calculates a cumulative impact force indicating the amount of work to be done based on the information such as the excitation force of the vibro-hammer acquired by the acquisition unit; and a display unit that displays the cumulative impact force calculated by the calculation unit. By sequentially checking the cumulative impact force calculated by the calculation unit on the display unit, the depth of the supporting layer can be determined in real time at the construction site for each object to be constructed, such as piles. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 5846592 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the depth of the bearing layer determined by the N-value may not be the same for each pile construction location. For this reason, it is desirable to investigate the depth of the bearing layer for each pile construction location, but this is not practical given the extremely large number of piles that are actually constructed.

[0009] Furthermore, the vibro-hammer construction machine described in Patent Document 1 basically works by applying forced vibrations to the object to be constructed, such as a pile, to rapidly and temporarily reduce the frictional resistance of the circumferential surface of the object to be constructed, and by the combined weight of the vibro-hammer and the pile exceeding the resistance force at the tip of the pile, the object to be constructed, such as a pile, can penetrate into the ground. However, this can take time for the object to be constructed to reach the supporting layer, and work efficiency can be significantly reduced, especially in hard soil layers.

[0010] The present invention was made to solve the above problems, and aims to provide a vibro-hammer pile driver equipped with a pile construction support system that can easily and reliably drive pre-fabricated piles, such as steel piles, to a depth having a predetermined support layer set by the N value, and can determine with high accuracy whether or not the tip of the pile has reached the predetermined support layer set by the N value. [Means for solving the problem]

[0011] The present invention comprises a leader equipped with a vibro-hammer for applying vibration to a pile, a hydraulic cylinder for pushing the pile into the ground via the leader, and a pile construction support system that provides an index for determining whether the tip of the pile has reached a supporting layer set by an N value, the pile construction support system comprising: a data input unit that acquires data including the operating hydraulic pressure of the hydraulic cylinder for pushing, the eccentricity of the eccentric weight of the vibro-hammer, and the penetration depth of the pile when the pile penetrates the ground; a calculation unit that calculates the pushing force of the hydraulic cylinder, the pushing speed, and the excitation force of the vibro-hammer from the data acquired by the data input unit, and the calculated pushing force, pushing speed, and Before The device is characterized by having a display unit that shows the correlation between each recorded excitation force value and a previously investigated N value.

[0012] The calculation unit is configured to calculate the operating hydraulic pressure of the pushing hydraulic cylinder, the eccentricity of the eccentric weight, and the penetration depth of the pile in unit quantities. It is also desirable that the unit be equipped with a storage unit that organizes and stores the calculated values ​​of the pushing force, pushing speed, and excitation force as data. [Effects of the Invention]

[0013] According to the vibro-hammer pile driver of the present invention, by using two devices, a vibro-hammer and a hydraulic cylinder for pushing, piles such as steel piles and sheet piles can be constructed very efficiently down to a support layer predetermined by the N-value.

[0014] Furthermore, by calculating the pushing force and speed of the pile by the hydraulic cylinder and the excitation force of the vibro-hammer from the operating hydraulic pressure of the hydraulic cylinder used for pushing during pile construction, the eccentricity of the eccentric weight of the vibro-hammer, the pile penetration depth, and the penetration time, and by showing the correlation between these calculation results and the N-value investigated in advance, it is possible to determine with high accuracy whether or not the tip of the pile has reached the pile bearing layer set by the N-value. [Brief explanation of the drawing]

[0015] [Figure 1] This is a side view of the basic configuration of a vibro-hammer pile driver equipped with the pile construction support system of the present invention. [Figure 2] Figure 1 shows a vibro-hammer pile driver, a side view with the leader positioned higher than the base machine. [Figure 3] Figure 1 is an explanatory diagram of the vibro-hammer equipped in the vibro-hammer pile driver, where (a) is a front view and (b) is a side view. [Figure 4] Figure (a) is a perspective view of the leader, and Figure (b) is a perspective view of the vibro-hammer lifting device installed inside the leader and equipped with a hydraulic cylinder for pushing the vibro-hammer up and down along the leader. [Figure 5] This is an explanatory diagram illustrating the principle of excitation force generation. [Figure 6] This is an explanatory diagram showing the configuration of a pile construction support system. [Figure 7] This graph shows the correlation between the pile-pushing force P1 by the hydraulic cylinder used for pushing and the N value. [Modes for carrying out the invention]

[0016] Figures 1 to 7 illustrate one embodiment of a pile driver equipped with the pile construction support system of the present invention, which includes a press-in combined vibro-hammer pile driver 2 for driving steel piles, sheet piles, etc. (hereinafter referred to as "piles") a into the ground, and a pile construction support system 3 that calculates an index in real time for determining the depth of the supporting layer of piles a.

[0017] The vibro hammer pile driver 2 using press-in combines a base machine 4, a leader 5 vertically erected on the advancing direction side of the base machine 4, a support arm 6 attached to the advancing direction side of the base machine 4 and supporting the leader 5, and a vibro hammer 7 attached to the leader 5 so as to be able to move up and down and imparting vibration to the pile a.

[0018] The support arm 6 includes links 6a, 6b, and 6c arranged in order in the advancing direction of the base machine 4 between the base machine 4 and the leader 5, and a plurality of hydraulic cylinders 8 for leader operation arranged on both the upper and lower sides of the links 6a, 6b, and 6c.

[0019] The links 6a, 6b, and 6c are each rotatably connected to each other in the vertical direction, and the end of the link 6a on the side of the base machine 4 is rotatably connected to the side of the base machine 4 in the vertical direction. Further, the link 6c is installed parallel to the leader 5 on the side of the leader 5.

[0020] The leader 5 is attached to the side of the link 6c via upper and lower brackets 9, 9, and is attached so as to slide vertically along the link 6c by a hydraulic cylinder 10 for leader lifting in a state where the link 6c is vertically arranged.

[0021] The hydraulic cylinder 10 for leader lifting is installed between the link 6c and the leader 5 along the link 6c and the leader 5. Further, the lower end of the hydraulic cylinder 10 for leader lifting is connected to the lower end of the link 6c, and the upper end is connected to the upper side of the leader 5.

[0022] Then, in the operation room 11 provided in the base machine 4, by operating the plurality of hydraulic cylinders 8 for leader operation, the leader 5 stands vertically on the tip side of the base machine 4, and the inclination, height, etc. of the leader 5 can freely change. Further, by operating the hydraulic cylinder 10 for leader lifting in the operation room 11, the leader 5 moves up and down along the link 6c.

[0023] Furthermore, a vibro-hammer lifting device 13 is installed inside the leader 5, which is equipped with a hydraulic cylinder 12 for pushing the vibro-hammer 7 up and down.

[0024] The vibro-hammer lifting device 13 includes an upper pulley 14 and a lower pulley 15 positioned above and below the hydraulic cylinder 12 for pushing, respectively, and an intermediate pulley 16 positioned between the upper pulley 14 and the lower pulley 15 and connected to the cylinder rod of the hydraulic cylinder 12 for pushing.

[0025] Furthermore, it is equipped with multiple ascending ropes 17a and descending ropes 17b wound around an upper pulley 14, a lower pulley 15, and an intermediate pulley 16, and a mounting plate 18 to which a vibro hammer 7 is attached between the ascending ropes 17a and the descending ropes 17b.

[0026] Then, by operating the hydraulic cylinder 12 for pushing in from the control room 11, the upward rope 17a and the downward rope 17b are wound onto one side, causing the vibro-hammer 7 to move up and down along the leader 5, thereby driving the pile a that the vibro-hammer 7 grips into the ground.

[0027] In this configuration, the vibro-hammer 7 descends along the leader 5, and at the same time, vibrations are applied to the pile a by the vibro-hammer 7. As a result, the pile a, which is erected along the leader 5, is forcibly and very efficiently driven into the ground by the pushing force P1 of the hydraulic cylinder 12 and the excitation force P2 of the vibro-hammer 7.

[0028] Furthermore, as shown in Figure 4(b), by using the pulley and the fixed pulley to transmit the operating hydraulic pressure of the pushing hydraulic cylinder 12 to the vibro-hammer 7 as the pushing force P1 of pile a, pile a can be driven into the ground very efficiently.

[0029] The vibro-hammer 7 includes a chuck 19 that grips the upper end of the pile a, a vibrator 20 that applies vibration to the pile a via the chuck 19, and a motor 21 that serves as a power source to operate the vibrator 20.

[0030] The vibrator 20 is equipped with at least one pair of eccentric weights 22, 22, which are arranged adjacent to each other horizontally and rotate in opposite directions by being operated in the control room 11 of the base machine 1. This generates a vibrating force P2 in the vertical direction (axis direction of pile a) according to the rotation period of the eccentric weights 22, 22 (see Figure 5).

[0031] Furthermore, the eccentric weights 22,22 can have their eccentricity arbitrarily set by remote control from the control room 11, and the eccentricity of the eccentric weights 22,22 changes as they move in the diametrical direction of their respective rotation axes 23,23.

[0032] Furthermore, the excitation force P2 changes in proportion to the change in the eccentricity of the eccentric weights 22,22, and the excitation force P2 increases as the eccentricity of the eccentric weights 22,22 increases.

[0033] Furthermore, the rotational speed of the eccentric weights 22, 22 corresponds to the number of blows that strike the pile head of pile a, and the number of blows can be adjusted by remotely controlling the operating hydraulic pressure of the motor 21 from the control room 11 located in the base machine 1.

[0034] For example, when the friction on the surface of pile a is high, the excitation force P2 can be increased by setting a large eccentricity in the eccentric weights 22, 22, and the number of blows can be increased by increasing the operating hydraulic pressure of the motor 21, thereby easily penetrating even soil layers with high surface friction.

[0035] In this configuration, the vibration force P2 of the vibro-hammer 7 temporarily releases friction on the surface of pile a, and the combined weight of the vibro-hammer 7 and the pile a exceeds the resistance of the soil layer at the tip of pile a, causing pile a to penetrate into the ground. Furthermore, with the addition of the pushing force P1 of the hydraulic cylinder 12, pile a can be reliably pressed into the ground up to a predetermined support layer set by the N value.

[0036] The pile construction support system 3 includes a data input unit 24 that captures data in real time indicating the operating hydraulic pressure of the pushing hydraulic cylinder 12 when pile a penetrates the ground, data indicating the eccentricity of the eccentric weights 22, 22 on the vibro hammer 7, and data indicating the penetration depth of pile a and the time it takes to reach that penetration depth.

[0037] Furthermore, the pile construction support system 3 includes a calculation unit 25 that calculates the pushing force P1 and pushing speed of the pushing hydraulic cylinder 12, and the excitation force P2 of the vibro hammer 7, respectively, from the hydraulic fluid pressure of the pushing hydraulic cylinder 12, the eccentricity of the eccentric weights 22, 22, the penetration depth of pile a, and the time it takes to reach the penetration depth.

[0038] Furthermore, the pile construction support system 3 includes a display unit 26 that displays in real time the correlation between the values ​​of the pushing force P1 of the hydraulic cylinder 12 for pushing the pile a, the pushing speed, and the excitation force P2 of the vibro-hammer 7, which are calculated in the calculation unit 25, and the N value that has been investigated in advance.

[0039] The N-value is determined in advance by standard penetration tests on the geological layers near pile a.

[0040] In this configuration, the hydraulic fluid pressure of the pushing hydraulic cylinder 12, the eccentricity of the eccentric weights 22, 22, the penetration depth of the prefabricated pile a, and the time it takes to reach each penetration depth are input to the data input unit 24 and processed in the calculation unit 25. From these, the pushing force P1 and pushing speed of the pushing hydraulic cylinder 12 applied to the pile a, and the excitation force P2 of the vibro hammer 7 are calculated in real time.

[0041] Then, the display unit 26 shows the correlation between the pressing force P1 of the hydraulic cylinder 12 for pressing the pile a, the pressing speed, and the excitation force P2 of the vibro-hammer 7, and the previously investigated N value, in real time along with the condition of the supporting layer. Mu It will be displayed as follows.

[0042] Furthermore, the results calculated by the calculation unit 25 are taken into the storage unit 26 as data, organized and stored, and retrieved as needed to create documents such as construction reports.

[0043] Furthermore, other construction personnel can also check construction information using dedicated remote monitoring terminals, even if they are located away from the construction site of pile a.

[0044] Figure 7 is a graph showing the correlation between the pushing force P1 of pile a by the hydraulic cylinder 12 and the previously investigated N value. [Industrial applicability]

[0045] The present invention allows for easy and reliable penetration of piles, such as steel piles, to a predetermined support layer set by the N-value, and enables highly accurate determination of whether the tip of the pile has reached the predetermined support layer. [Explanation of symbols]

[0046] 1. Pile driver equipped with a pile construction support system. 2. Vibro-hammer pile driver, 3. Pile construction support system, 4 base machine, 5 leader, 6 support arm 6a, 6b, 6c links, 7 vibro-hammer 8. Hydraulic cylinder for leader operation, 9. Guide 10 Hydraulic cylinder for lifting and lowering the leader, 11 Control room 12. Hydraulic cylinder for pushing, 13 Vibro-hammer lifting device, 14 Upper pulley 15 Lower pulley, 16 Intermediate pulley, 17a Ascending rope 17b Descending rope, 18 Mounting block, 19 Chuck, 20 Vibrator, 21 Motor, 22 Eccentric weight, 23 Rotating shaft, 24 Data input section, 25 calculation section, 26 display section, 27 storage section

Claims

1. A vibro-hammer pile driver equipped with a pile construction support system comprising: a leader equipped with a vibro-hammer for applying vibration to a pile; a hydraulic cylinder for pushing the pile into the ground via the leader; and a pile construction support system that provides an index for determining whether or not the tip of the pile has reached a supporting layer set by an N-value, wherein the pile construction support system comprises: a data input unit that takes in data including the operating hydraulic pressure of the hydraulic cylinder for pushing, the eccentricity of the eccentric weight of the vibro-hammer, and the penetration depth of the pile when the pile penetrates the ground; a calculation unit that calculates the pushing force of the hydraulic cylinder, the pushing speed, and the excitation force of the vibro-hammer from the data taken in by the data input unit, respectively; and a display unit that displays the correlation between the values ​​of the pushing force, the pushing speed, and the excitation force and a previously investigated N-value.

2. A vibro-hammer pile driver equipped with the pile construction support system described in claim 1, wherein the calculation unit is configured to calculate the pushing force of the pushing hydraulic cylinder, the pushing speed, and the excitation force of the vibro-hammer for each unit amount of the pile penetration depth from the data taken into the data input unit.

3. A vibro-hammer pile driver equipped with the pile construction support system according to claim 1 or 2, characterized in that it is equipped with a storage unit that organizes and stores the values ​​of the pressing force, the pressing speed, and the excitation force as data.

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