JP3683509B2 - Dynamic press-fitting propulsion method and propulsion device used in this method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a dynamic press-fitting propulsion method and a propulsion device used in this method, and in particular, embedment of underground lines such as telecommunications pipes, sewer pipes, gas pipes, etc. in the ground dynamically. The present invention relates to a dynamic press-fitting propulsion method and a propulsion device used in this method.
[0002]
[Prior art]
Conventionally, in the case of embedding telecommunications pipes, sewer pipes, gas pipes and the like in the ground, the non-cutting propulsion method is generally employed. When laying pipes in the ground by this non-open-cut propulsion method, the propulsion method by non-draining press-in is performed on relatively soft ground such as cohesive soil. In this propulsion method by non-extruded soil injection, a starting shaft is first formed on the ground, a main pushing device is installed on the starting vertical shaft, and the leading conductor is pushed from the main pushing device to the ground in the direction of laying the pipeline, Following this tip conductor, the propulsion pipe is laid continuously following the tip conductor. The following types of propulsion methods using undischarged soil injection are known.
[0003]
(1) Simple press-fitting method As shown in FIG. 1, the lead conductor 4 and the propelling pipe 5 following the lead conductor 4 are press-fitted into the ground 1 at once using the main pushing device 3 installed in the start shaft 2. This is a simple press-fitting method for propulsion and a static press-fitting propulsion method.
[0004]
(2) Press-fitting method by double propulsion As shown in FIG. 2 (a), the front conductor 4 having the tip head 6 mounted on the tip is provided, and the total propulsion force is applied to the tip 6 of the tip of the lead conductor 4 on the front surface. This is a press-fitting method by double propulsion having a double propulsion mechanism that enables propulsion by dispersing the propulsion pipe 5 that follows the resistance force and the friction resistance force caused by friction between the ground 1 and a static press-fitting propulsion method. At the time of propulsion, as shown in FIG. 2 (b), the tip head 6 mounted on the leading conductor 4 is propelled by a double propelling jack 7 built in the leading conductor 4, and thereafter, as shown in FIG. 2 (c). As described above, this is a press-fitting method by double propulsion in which the leading conductor 4 and the propelling pipe 5 are propelled by the main pushing device 3 installed in the start shaft 2.
[0005]
(3) Press-in method by eccentric rotation of the tip head As shown in FIG. 3, the tip head 8 has a leading conductor 4 equipped with a dynamic operating mechanism for efficiently removing soil, and the tip head As shown in FIGS. 4 (a) to 4 (c), 8 is eccentrically rotated with respect to the leading conductor 4, and in this state, the leading conductor 4 and the propelling pipe 5 are used by using the main pushing device 3 installed in the starting shaft 2. Is a rotary press-fitting method in which the material is pressed into the ground 1 and is a dynamic press-fitting method.
[0006]
(4) Press-fitting method by rotational vibration As shown in FIG. 5, the tip head 8 has a leading conductor 4 equipped with a dynamic operation mechanism for efficiently removing soil, as shown in FIG. 6 (a). As shown in FIGS. 6 (a) to 6 (c), a weight 9 and an eccentric rotation mechanism (not shown) are provided inside the tip head 8 as shown in FIG. The weight 9 is rotated to generate vibration in the outer peripheral direction from the center of the leading conductor, and in this state, the leading conductor 4 and the propelling pipe 5 are press-fitted into the ground 1 using the main pushing device 3 installed in the start shaft 2. This is a rotary vibration type press-fitting method, which is a dynamic press-fitting method.
[0007]
(5) Impact-type press-fitting method As shown in FIG. 7, a tip conductor 4 having a sharp tip and a propelling tube 5 following the tip conductor 4 are provided. Yes, compressed air is guided by the air hose 11 from the compressor 10 installed on the ground 1 to the weight, and the weight is moved back and forth to generate an impact force at the tip of the leading conductor 4, and in this state, it is allowed to self-run. This is a rotary vibration type press-fitting method in which the tip conductor 4 and the propelling pipe 5 are press-fitted into the ground 1, and is a dynamic press-fitting method.
[0008]
Thus, compared with the propulsion method using the excavation and excavation method, any press-fitting method has a faster excavation speed because it does not include a excavation mechanism using a cutter head and an exhaust mechanism for discharging excavated earth and sand. Since the system configuration is simple and the system price is low, the construction period can be shortened and the construction cost can be reduced. In addition, it has the feature that it contributes to the protection of the natural environment because it is free of soil.
[0009]
[Problems to be solved by the invention]
However, in soft and homogeneous ground such as a viscometer, there is no problem with construction by a simple press-fitting method or double propulsion method, but the ground is a double-layered ground of sandy soil and viscous soil, sandy soil or soil mixed with reki, etc. In the hard ground, the simple press-fitting method (1) has a problem that the total thrust of the main pushing device installed in the start shaft is weak.
[0010]
In addition, in the press-fitting method with double propulsion (2), the total thrust is distributed to the front resistance of the tip head and the friction resistance of the pipe peripheral surface of the propulsion pipe following the leading conductor, but to the tip. The front resistance for press-fitting the lid is increased, and the soil quality has a problem that the application is limited to an N value of about 15.
[0011]
On the other hand, in the press-fitting method by eccentric rotation of the tip head (3), which is a dynamic press-fitting propulsion method, in order to expand the application of soil properties, the tip of the tip head is not suitable for hard ground such as sandy soil or mixed soil. Since the torque required for the eccentric rotation is limited in terms of equipment , there is a problem that a sufficient reduction effect of the front resistance cannot be expected.
[0012]
In addition, in the press-fitting propulsion method using the rotational vibration of (4), the tip conductor cannot be vibrated only at the tip and the entire tip conductor is vibrated. Therefore, the tip conductor is tightened from the ground due to the water-tightening effect on the ground with a high groundwater level. However, there is a problem that it becomes impossible to promote the leading conductor, and the application of soil quality has not been extended to practical use.
[0013]
Furthermore, in the impact-type press-fitting propulsion method of (5), although propulsion is possible on hard ground, the propulsion distance is limited due to the use of compressed air, and the vibration and noise for generating impact force are severe, There was a problem that its application was restricted due to the environmental conditions of the construction site.
[0014]
Therefore, the present invention eliminates the problems of the conventional press-fitting method, and even in hard ground, the pipe line can be embedded by the propulsion method by non-draining press-fitting method, and the ground that has been carried out by the excavation and excavation method of propulsion method so far The purpose of the present invention is to provide a dynamic press-fit propulsion method capable of press-fitting propulsion without soil and a propulsion device used in this method.
[0015]
In addition, the dynamic press-fitting propulsion method that can suppress vibrations, can be constructed without causing noise problems, and contribute to the protection of the natural environment without generating soil, and this method. The object is to provide a propulsion device to be used.
[0016]
[Means for Solving the Problems]
The dynamic press-fitting propulsion method of the present invention that achieves the above object is to propel and push a tip conductor having a tip head at the tip into the ground using a main pushing device installed in a start shaft. This is a dynamic press-fitting propulsion method with non-draining press-fitting to follow the pipe, and the tip head is configured to be able to vibrate inside the tip conductor or by a vibration generator mounted on the main pusher, and the tip head is parallel to the propulsion direction. The soil is vibrated in the longitudinal direction to give a predetermined vibration acceleration to the ground, and this vibration acceleration reduces the shear strength of the ground to fluidize the soil particles in the vicinity of the tip head of the ground, resulting in a resistance force effect on the front surface of the tip head. It is characterized in that excavation is carried out in a state where the slag is reduced to the maximum, and press-fitting is possible without soiling up to an N value of about 30.
[0017]
In this case, the predetermined vibration acceleration can be a vibration acceleration with a frequency around the natural vibration frequency of the ground so that the ground is in a resonance state.
[0018]
Further, the propulsion device used in the dynamic press-fitting propulsion method of the present invention that achieves the above object is a main pushing device installed in the start shaft, and a propellant that is propelled by the main pushing device and then follows the propelling pipe. A tip conductor with a tip head in the part, a vibration generator mounted on the inside of the tip conductor or in the main pushing device and vibrating the tip head, and a predetermined vibration in the front-rear direction parallel to the propulsion direction of the tip head And a control device that controls the vibration generating device so as to vibrate with acceleration.
[0019]
In this case, sensors are mounted inside the leading conductors, and the detection values of these sensors are taken into a calculation device provided in the control device, and the frequency, amplitude, and vibration force that minimize the front resistance of the tip head are calculated. The tip head can be configured to generate the optimum frequency, amplitude, and vibration force according to the ground conditions.
[0020]
According to the dynamic press-fitting propulsion method of the present invention and the propulsion device used in this method, it is possible to embed a pipe line from a cohesive soil to a ground such as sandy soil or sand repellent by a propulsion method by non-exhaust soil press-fitting. It is possible to press-fit without soil removal even on the ground that has been excavated and expelled. For this reason, in the propulsion method of the present invention by non-extruding press-fitting that vibrates the tip head in a direction parallel to the propulsion direction, since the excavation mechanism and the excavation mechanism are not mounted, the construction period can be shortened because the excavation mechanism and the excavation mechanism can be carried out at high speed. Because the system is simple, the cost of the equipment is low, and industrial waste such as earth removal is not generated, so construction costs can be greatly reduced.
[0021]
In addition, since vibration can be suppressed to a minimum, construction can be performed without causing problems such as noise. Furthermore, since industrial waste such as soil discharge is not generated, it can contribute to the protection of the natural environment.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail below based on specific examples with reference to the accompanying drawings. In addition, in the structure of the Example of this invention, the same code | symbol is attached | subjected and demonstrated to the same structural member as the structural member of the conventional apparatus demonstrated in FIGS.
[0023]
FIG. 8 shows the structure of an embodiment of a propulsion device used in the dynamic press-fitting propulsion method of the present invention. The propulsion device of this embodiment also uses the main pushing device 3 installed in the start shaft 2 to press the propellant 4 having the tip head 12 at the tip into the ground 1 and propel it, and the propulsion tube 5 is a dynamic press-fitting propulsion method that follows 5. The tip head 12 can be vibrated in a direction parallel to the propulsion direction by a drive mechanism (not shown). The driving mechanism of the tip head 12 can be a vibration generating mechanism mounted on the main pushing device 3 installed in the leading conductor 4 or on the start shaft 2. In this embodiment, the shape of the propulsion head 12 is flat, but may be a cone type.
[0024]
By the way, when the vibration acceleration of 0.3 to 0.4 G or more is applied to the ground, the shear strength of the ground decreases due to the application of the vibration acceleration shown in FIG. It is generally known that particle fluidization occurs. In order to maximize the effect of lowering the shear strength of the ground by applying such vibration acceleration, it is necessary to bring the ground into a resonance state.
[0025]
Considering the ground as a forced damped vibrator, a forced damped vibration model as shown in FIG. 10 is completed. FIG. 11 is a graph showing the general solution of this forcedly damped vibration model with the frequency and acceleration or amplitude as axes. From this graph, if the vibration acceleration is applied to the ground before and after the natural vibration frequency (denoted as the natural frequency in the figure) in a resonance state (peak portion of the graph), the shear strength of the ground can be reduced most efficiently. Further, when the vibration force is increased, the acceleration or amplitude capable of generating a resonance state is increased, so that an effect of lowering the shear strength of the ground can be expected.
[0026]
From this, the vibration acceleration around the natural frequency of the ground is applied by vibrating the head 12 of the tip of the leading conductor 4 shown in FIG. In addition to being able to reduce, it is possible to fluidize the soil particles temporarily and locally, enabling efficient rearrangement of the soil particles, and greatly reducing the front resistance force due to the press-fitting of the leading conductor 4 It will be possible.
[0027]
FIG. 12 shows the effect of reducing the front resistance applied to the tip head 12 of the leading conductor 4 when the dynamic press-fitting propulsion method of the present invention is used in sandy ground having an N value of about 20 using the frequency as a parameter. Is. FIG. 13 shows the effect of reducing the frontal resistance force applied to the head 12 of the tip of the leading conductor 4 in the static simple press-fitting method and the dynamic press-fitting propulsion method of the present invention, using the N value as a parameter. .
[0028]
In the present invention, since the dynamic method of vibrating only the tip head 12 in parallel with the propulsion direction is used even on hard ground such as sand mixed with sandy soil, the above-mentioned is applied only to the front surface of the leading conductor 4. It is characterized by the effect of vibration acceleration. FIG. 12 is a graph showing the effect of reducing the front resistance by the dynamic press-fitting propulsion method of the present invention on the target hard soil ground (N value of about 20), and giving the ground a frequency of about 10-20 Hz. Thus, the front resistance applied to the head 12 at the tip of the leading conductor 4 can be reduced by 30% or more.
[0029]
Further, as shown in FIG. 13, when the equipment capacity of the leading conductor 4 is assumed to be 1000 kN, the conventional static press-fitting propulsion method has a limit of up to about N value 15, but the dynamic press-fitting of the present invention. In the propulsion method, it is possible to dig to the hard ground having the soil N value of about 30 with the same equipment ability by the above-described vibration acceleration effect.
[0030]
Furthermore, in the dynamic press-fitting propulsion method according to the present invention, as shown in FIG. 14, sensors such as a displacement meter 13 of the tip head 12, a load transducer 13, and an accelerometer 15 are built in the leading conductor 4. The detection data from these sensors is input to the operation panel 17 through the arithmetic unit 16 and the measurement result is displayed on the monitor 18. Further, a control signal to the tip head 12 is also transmitted from the operation operation panel 17 to the leading conductor 4 via the calculator 16.
[0031]
Based on information from the sensor mounted in the leading conductor 4, the operator of the propulsion device of the present invention monitors the front resistance force, vibration force, vibration frequency, acceleration, amplitude, etc. of the tip head 12 on the monitor 18 in real time. It is possible to perform optimal vibration control that minimizes the front resistance of the leading conductor according to the ground conditions. Specifically, the operator can perform vibration control that gives vibration acceleration at a natural frequency corresponding to the ground to the ground and increases the vibration force to maximize the amplitude. That is, according to the control method of the present invention, the resonance state shown in FIG. 11 is always generated, and the effect of vibration acceleration can be increased by increasing the vibration force. An effect is obtained.
[0032]
From the above, the dynamic press-fitting propulsion method using the propulsion device of the present invention has no effect even on relatively hard ground, which has been carried out by excavation and soiling methods, such as clay soil, sandy soil, and mixed soil. The excavation can be performed at high speed by press-fitting the earth. For this reason, in the dynamic press-fitting propulsion method of the present invention, the excavation work period in a relatively hard ground can be shortened, and since no industrial waste is generated, the construction cost can be greatly reduced. In addition, since vibration can be suppressed to a minimum, problems such as vibration noise to the surroundings can be solved. Furthermore, since the applicable range of soil quality and caliber that can be press-fitted without draining is expanded, the generation of industrial waste can be further suppressed, which can greatly contribute to the protection of the natural environment.
[0033]
【The invention's effect】
As explained above, according to the dynamic press-fitting propulsion method using vibration parallel to the propulsion direction by the tip head of the present invention, the propulsion method by non-draining press-fitting from clay soil to ground such as sandy soil and sand repellent soil. The pipe can be buried with. In addition, it is possible to carry out press-fitting propulsion without soil even on the ground that has been excavated and expelled. For this reason, in the propulsion method of the present invention by non-extruding press-fitting that vibrates the tip head in a direction parallel to the propulsion direction, since the excavation mechanism and the excavation mechanism are not mounted, the construction period can be shortened because the excavation mechanism and the excavation mechanism can be carried out at high speed. Since the system is simple, the price of the apparatus is low, and industrial waste such as earth removal is not generated, so that the construction cost can be greatly reduced.
[0034]
In addition, since vibration can be suppressed to a minimum, it can be constructed without causing problems such as noise. Furthermore, since industrial waste such as soil is not generated, it can contribute to the protection of the natural environment. effective.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a conventional propulsion device that performs a simple press-fitting method.
FIG. 2 shows a conventional press-fitting type propulsion device using double propulsion , where (a) shows a state before propulsion of the tip head, (b) shows a state in which the tip head is propelled by a double propulsion jack, (c ) Is a diagram showing a state in which the leading conductor and the propelling pipe are made to follow the propelled tip head.
FIG. 3 is a view showing a press-fitting type propulsion apparatus in which a conventional tip head rotates eccentrically.
4 (a) to (c) are diagrams for explaining the eccentric rotation of the tip head of the propulsion device shown in FIG. 3. FIG.
FIG. 5 is a diagram showing a press-fitting type propulsion device in which a conventional tip head rotates and vibrates.
6 (a) to 6 (c) are diagrams for explaining rotational vibration of a tip head of the propulsion device shown in FIG.
FIG. 7 is a view showing a press-fitting type propulsion device in which a conventional tip head is subjected to shock vibration.
FIG. 8 is a diagram showing a dynamic press-fitting propulsion device according to an embodiment of the present invention.
FIG. 9 is a graph showing a state in which the shear strength of soil is lowered due to application of vibration acceleration.
FIG. 10 is a diagram showing a forced damped vibration model when the ground is considered as a forced damped vibrator.
11 is a graph showing the relationship between the frequency and acceleration or amplitude of the forcedly damped vibration model of FIG.
FIG. 12 is a diagram showing the frequency reduction effect on the sand ground of the vibration method using the dynamic press-fitting type propulsion device of the present invention and the effect of reducing the front resistance force at the tip of the leading conductor.
FIG. 13 is a graph showing the N value and the effect of reducing the front resistance force at the tip of the leading conductor in the sand ground of the vibration method using the dynamic press-fitting propulsion device of the present invention.
14 is a system diagram showing a control method for performing optimal vibration control of the dynamic press-fitting propulsion device of FIG. 8; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ground 2 Starting shaft 3 Main pushing device 4 Leading conductor 5 Propulsion pipe 6 Tip head 7 Double propulsion jack 8 Tip head 9 Weight 12 Tip head 13 Displacement meter 14 Load transducer 15 Accelerometer 17 Operation control panel 18 Monitor

Claims (2)

The leading conductor (4) with the tip head (12) at the tip is pressed into the ground (1) using the main pushing device (3) installed in the start shaft (2) and propelled to this. A dynamic press-fitting propulsion method by non-draining press-fitting to follow the pipe (5),
The tip head (12) is configured to be vibrated by a vibration generator mounted in the leading conductor (4) or in the main pushing device (3),
The tip head (12) is vibrated in the front-rear direction parallel to the propulsion direction and is inherent to the ground (1) based on information from a sensor mounted on the ground (1) inside the leading conductor (4). Giving vibration acceleration at frequencies around the vibration frequency, and making the ground (1) in a resonance state,
Due to this vibration acceleration, the soil (1) is reduced in shear strength to fluidize soil particles in the vicinity of the tip head (12) of the ground (1),
Performing excavation in a state where the resistance force on the front surface of the tip head (12) is reduced,
Dynamic press-fit propulsion method characterized by enabling press-fitting without soiling up to an N value of about 30. A propulsion device used in the dynamic press-fitting propulsion method according to claim 1 ,
A main pushing device (3) installed in the start shaft (2),
Driven by the main pushing device (3) through a propelling pipe (5) to be followed later, a tip head (12) at the tip, and a leading conductor (4) having a sensor inside,
A vibration generator mounted on the inside of the leading conductor (4) or on the main pushing device (3) and vibrating the tip head (12);
A control device for controlling the vibration generating device so as to vibrate the tip head (12) at a predetermined vibration acceleration in the front-rear direction parallel to the propulsion direction;
An arithmetic unit that takes in the detection value of the sensor and calculates the vibration frequency, amplitude, and vibration force that minimize the front resistance of the tip head (12);
With
A propulsion device used in the dynamic press-fitting propulsion method, wherein the tip head (12) generates the vibration frequency, amplitude, and vibration force calculated by the arithmetic device.

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