JP3086422B2 - Shield construction method and shield excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield method (tunnel excavation method) for excavating a tunnel having a continuous section of a plurality of circles at a time, and a shield machine used for carrying out the method.

[0002]

2. Description of the Related Art A shield excavator has a rotary cutter in front of a cylindrical body, and drives a rotary cutter to excavate a tunnel having a circular cross section in the ground. As the propulsion means, for example, a shield jack is provided, and a forward thrust is obtained by pushing the front end face of the segment wall constructed rearward as a support backward.

[0003] In recent years, a shield machine for excavating a tunnel having a cross section of a plurality of circles (a plurality of substantially circular portions) at a time has been put into practical use. This is because a tunnel with such a cross section is convenient for laying a double track for a train or passing through a multi-lane motorway. The shield machine for this purpose is basically configured as a plurality of body portions having a rotary cutter in front thereof arranged in parallel. By excavating a circular portion, each trunk having each circle forms a tunnel having a continuous section of a plurality of circles as a whole.

When excavating a multi-circle tunnel with such a shield excavator, the excavator itself is rolled, that is, rotated around a center line along the front-rear direction. Angle in the cross section) may be changed appropriately. If the relationship of each circle is changed from horizontal to diagonal or vertical, for example, in a place where there is no restriction on the excavation path, a horizontal double tunnel where two circles are arranged horizontally is excavated, This makes it possible to excavate a vertical double tunnel with two circles above and below, which is convenient.

[0005] As a structure for changing the positional relationship between the circles, pins (including bolts and the like) are provided so that the plurality of body portions can change the mutual angle while partially joining the respective side surfaces. Shafts).
When changing the angle between the multiple torso with a part of the side joined, and then proceeding with the shield excavator, the torso tries to advance in the direction of each angle, but the torso is connected with pins Because of this, the entire shield machine will advance in a spiral (ie, like a screw) rolling motion. The reason for the connection by the pin is that the connection by welding or the like cannot be performed because the angle between the body portions needs to be changed. Regarding the connection, it is a matter of course that the fastening force exerted on the joint surfaces is appropriately determined so that a frictional force large enough to prevent the above-mentioned angle change is not generated between the joint surfaces. The structure in which the trunk portions are connected by pins is described in Japanese Patent Application Laid-Open No. Hei 5-93497.

[0006]

In a shield excavator having a plurality of trunks, a load is applied to a pin connecting the trunks when the excavator is rolled or the like, and a relatively large axial force (that is, an axial force) is generated. It is thought that the tensile force in the longitudinal direction (or the tensile stress generated on the pin thereby) acts. However, conventionally, the specific magnitude of the axial force has not been clarified. In addition, no effort has been made to actively grasp the magnitude of the axial force and reflect it in the manufacture and operation of the shield machine.

Therefore, conventionally, various wastes have been involved in manufacturing or operating a shield machine.
It can be said. For example, since the magnitude of the axial force cannot be grasped, there is a case where a pin is extremely thickened to have sufficient strength and an extremely thick steel plate is used for a body (joining surface portion) joined by the pin. During drilling, for example, it is not possible to determine the extent of the soil and the operating conditions of the ground, and if there is any inconvenience such as permanent deformation of the pin and its surroundings, the drilling speed must be reduced, and the performance of the shield drilling machine must be sufficiently improved. Sometimes it can't be used. In addition, there is a case where the labor and time of the operator are particularly required to check the pins and the surrounding parts. Such a point,
It can be considered that the waste is caused by not grasping the axial force of the pin.

[0008] The invention of the present application is to positively grasp the axial force acting on the pin for connecting the trunks, and to manufacture and operate the shield machine so as to reduce waste by utilizing the result. With the goal.

[0009]

According to the first aspect of the present invention, there is provided a shield construction method in which a plurality of body portions each having a rotary cutter in front thereof can change an angle between them while a part of each side surface is joined. A shield construction method that uses a shield machine connected by pins (shafts including bolts and the like) to excavate a tunnel having a continuous cross section of a plurality of circles,
During excavation, the axial force (tensile force or tensile stress in the axial direction) acting on the pin is measured, and one or more of the angle between the trunks, the rotation speed of the cutter, and the excavation speed are measured. Is operated so as not to be excessive.

In this shield method, first, a tunnel having a continuous section of a plurality of circles can be excavated at a time because the shield excavator having a plurality of trunks as described above is used. For those torso parts, the angle between them can be changed while keeping a part of each side joined,
It is possible to advance the excavator while rolling it as described above. By changing the position of the excavator by rolling, the positional relationship between the circular sections of the tunnel can be changed from horizontal (close to horizontal) to vertical (close to vertical) or vice versa. Can be changed.

When the shield machine is rolled, for example, an axial force is generated in the pins connecting between the trunks. According to the shield method of claim 1, the axial force is measured during excavation and the axial force is measured. Manipulate at least one of the angle between the trunks, the rotation speed of the cutter, and the excavation speed so that the axial force is not excessive. When the axial force is measured in this way to prevent it from becoming excessive, the following advantages are provided. In other words, 1) no undesired deformation of the pin and its surrounding joint surface is required, so that the excavator can be smoothly rolled and the tunnel can be dug smoothly at all times. 2) The ability of the excavator can be maximized within the range that does not cause permanent deformation of the pin according to the soil properties of the ground and operating conditions, etc., and tunnel excavation can be promoted more efficiently than ever it can. 3) Workers and the like do not need to frequently inspect the pins and their surroundings, so that the number of workers can be reduced. 4) Because it is possible to grasp the load of the pin, which was unknown in the past, when designing and manufacturing the shield machine, excessively thick pins and extremely thick steel plates were used for the joint surface of the trunk. Waste can be eliminated.

The reason why the excavation speed and the rotation speed of the cutter are determined so that the axial force of the pin does not become excessive is that the axial force of the pin changes with the change as conventionally known. However, according to the investigation by the inventors, the axial force increases as the angle between the trunks increases (the investigation result and the like will be described later). Therefore, while measuring the axial force of the pin, by appropriately operating and setting at least one of the angle between the trunks, the rotational speed of the cutter, and the excavating speed, the axial force is prevented from becoming excessive. You can do it.

[0013] The shield method according to claim 2 is characterized in that the pressure acting on the side surface of each trunk is measured, and the axial force of the pin is known from the pressure. The axial force of the pin is generated as a balance with the external force acting on the shield machine, and the external force that is strongly associated with the axial force of the pin is the pressure (earth pressure, Etc. pressure). Therefore, the axial force of the pin can be known by measuring the pressure on the side surface of each body and converting it based on the measured pressure. If the operating conditions such as the angle between the trunks are manipulated as described above (claim 1) while measuring the axial force, the same advantages as those of the above 1) to 4) can be naturally obtained.

According to a third aspect of the present invention, there is provided a shield machine, wherein a plurality of body portions each having a rotary cutter in front thereof are provided with pins (bolts or the like) so that the angle between them can be changed while a part of each side surface is joined. A shaft excavator connected by a shaft excavator), wherein a measuring means for measuring an axial force (tensile force or tensile stress in the axial length direction) is attached to the pin, and the measuring means (output part) is It is characterized in that it is connected to at least one of the angle changing means between the body parts, the rotation driving means of the cutter and the propulsion means.

This shield excavator can smoothly implement the shield method described in claim 1. That is, since a tunnel having a plurality of circles can be excavated because of having a plurality of trunks as described above, and the angle between the trunks can be changed, it is possible to change the positional relationship of the plurality of circles in the tunnel cross section by rolling. it can. Further, since the axial force of the pin is grasped by the measuring means attached to the pin, the excavation can be advanced while performing automatic control so that the axial force is not excessive. Excavation can be performed without excessively increasing the axial force of the pin. When the excavator detects the axial force of the pin with the measuring means, it sends the data to the control unit,
This is because the control unit automatically operates one or more of the angle between the trunks, the rotation speed of the cutter, and the excavation speed by the propulsion means so that the axial force does not become excessive. It should be noted that a fluid pressure cylinder, a motor, or the like is often used as a driving source of the angle changing means between the body parts, the rotation driving means of the cutter, and the driving means of the propulsion means. Therefore, the above-described control unit is generally configured to control the displacement or speed of the hydraulic cylinder or the motor via a pressure fluid or electric power.

According to a fourth aspect of the present invention, there is provided a shield machine wherein a pressure sensor is attached to a side surface of each body, and conversion means for obtaining an axial force of the pin from a detection value of the sensor is provided in the machine. It also has a feature in that it is used as a measuring means. According to such a shield machine, the pressure sensor and the conversion unit function as a pin axial force measurement unit according to claim 3. As described above, the pressure (earth pressure) on each side of the body detected by the pressure sensor is strongly linked to the axial force of the pin, and can be converted to the axial force. 5. The shield machine according to claim 4, wherein said pressure sensor and said converting means are connected to at least one of said angle changing means between said trunk portions, said cutter rotating drive means and said propulsion means as said measuring means. Similarly to the excavator of the third aspect, excavation can be smoothly advanced while controlling the axial force of the pin not to be excessive.

[0017]

1 to 7 show an embodiment of the present invention. 1 is a perspective view showing the outline of the shield machine 1 and its control equipment, FIG. 2 is a plan view of the machine 1 in the operating state of FIG. 1, and FIG. 3 is a longitudinal sectional view showing the structure of the machine 1 (FIG. 3 (a)) and a front view ((b)). 4 and 5 are data showing the results of the investigation. The axial force of the connecting pin 40 between the trunks and the angle between the trunks, which were simultaneously measured in the excavator 1 during excavation of the same portion, were measured in the respective vertical directions. This is an oscillograph drawn with the excavation distance on the horizontal axis and the horizontal axis.

As shown in FIGS. 3 (a) and 3 (b), the shield machine 1 is configured to excavate a tunnel having a cross section in which two circles having the same diameter are partially overlapped to form a continuous section. The parts 10 and 20 are connected in parallel to the front part. Body 10
The outer shape of each cross section 20 is symmetrical with respect to the joint surfaces 14 and 24 (described later). A generally cylindrical body 1
Rotary cutters 11 and 21 are disposed in front of the hydraulic motors 0 and 20 respectively, and as shown in FIG.
Rotation driving means 12 and 22 using 2a and 22a as driving sources are connected. As shown in FIG. 3B, a number of cutter bits 11a and 21a and copy cutters 11b and 21b are incorporated in each of the cutters 11 and 21. The positions of the cutters 11 and 21 are shifted back and forth as shown in FIG. 3A so that they do not come into contact with each other during rotation. Immediately behind the cutters 11 and 21, a cutter chamber 2 is formed as a common space, to which the water supply pipe 3 and the mud discharge pipe 4 are connected from behind.

As shown in FIGS. 1 and 3 (a), each body 10
20 has flat joining surfaces 14 and 24 formed on a part of the side surfaces and overlaps and joins them, and a common rear body 30 is connected to the rear portion. The side of the rear trunk 30 is the trunk 1
8 equivalent to connecting the cross-sections of 0.20
It is formed so as to have a U-shaped cross section. An erector (not shown) for assembling the segment S on the inner surface of the tunnel is provided inside the rear trunk 30, and a propulsion force is applied to the excavator 1 by pressing the tip spreader 32 against the end surface of the assembled segment S. The resulting plurality of shield jacks 31 are arranged as propulsion means.

Each of the trunks 10 and 20 is connected to the rear trunk 30 so as to be able to make a so-called middle bend (bend) in a plane parallel to the joint surfaces 14 and 24. That is, as shown in FIG.
A plurality of bending pins 33 are arranged on a straight line perpendicular to the lines 4 and 24, and brackets 16 and 26 provided at the rear of the body are rotatably connected to the pins 33. And between the trunk 10 and the rear trunk 30, and between the trunk 20 and the rear trunk 3
A plurality of center folding jacks 18 and 28 each of which provides a force for center folding between 0 and 0 are provided. Each torso 10.2
By making a difference in the amount of expansion and contraction of each of the jacks for each 0, the body portions 10 and 20 are folded in the middle with respect to the rear body 30, respectively. In addition, in order to prevent muddy water from entering the inside of the shield machine 1 (the space in which the rotary driving means 12 and 22 and the erectors are arranged) even at the time of the middle folding, a position including the extension of the pin 33 is used. A spherical curved surface 34 is formed on the outer periphery of the rear trunk 30, and packings 17 and 27 are provided at the rear portions of the trunks 10 and 20 so as to always contact the curved surface 34.

The above-mentioned jacks 18 and 28 for bending at the center
Are driven independently for each of the torso sections 10 and 20, so that the torso sections 10 and 20 can bend independently of the rear torso 30 to change the angle between them. However, since the body portions 10 and 20 bend in the plane parallel to the joining surfaces 14 and 24, respectively, around the above-described middle bending pin 33, and the joining surfaces 14 and 24 are connected by the connecting pins 40. , The joint surfaces 14 and 24 during the angle change
The joined state between them is maintained. The reason for maintaining such a joint state is to maintain the cross section of the tunnel in a continuous shape of two circles and to prevent earth and sand, muddy water, and the like from entering between the trunk portions 10 and 20. This is because it is impossible to change the angle between the trunks 10 and 20 by welding or the like. The pin 40 is, as shown in FIG.
One having one at one end and a nut 42 attached to the other end to sandwich the joint surfaces 14 and 24 is used. In addition,
Since the joint surfaces 14 and 24 slide relative to each other and relatively move, the connecting pins 4 on the joint surfaces 14 and 24
The 0 through holes are formed to be long in the sliding direction. That is, as shown in FIG. 2, a long hole 40a along a curve centered on the center bending pin 33 is formed in a portion of the joining surfaces 14 and 24 through which the connecting pin 40 passes, and the long hole 40a is formed in the long hole 40a. It passes through the connecting pin 40.

When the trunks 10 and 20 are aligned and bent in the same direction with respect to the rear trunk 30, the entire shield excavator 1 is advanced along a fixed curve, and the entire curved tunnel is formed. The shield excavator 1 can be rolled in the case where the trunks 10 and 20 are bent independently of each other based on the above configuration. By making only one of the two trunks 10 and 20 bend with respect to the rear trunk 30, or making both of them bend in different directions (directions forming a part of the spiral),
This is because, if an angle is formed between 0 and 20, the trunks 10 and 20 advance in different directions (spirals), and the entire shield excavator 1 advances as if rotating like a screw. When rolling is performed in this manner, the shield machine 1 changes into a state of two horizontal sections where the two trunks 10 and 20 are horizontally aligned with each other, and a state of two vertical sections vertically arranged with each other. It is possible to excavate a desirable tunnel whose positional relationship is appropriately changed.

When the shield machine 1 is rolled, a considerable axial force (ie, tensile force or tensile stress) acts on the connecting pin 40. Two torso 10 at different angles
The reason why the body 20 advances while rotating helically instead of separating and proceeding in the direction of each axis is that the body 40 is pulled by the pin 40, During rolling, an axial force corresponding to the force
It acts on If an excessive axial force is applied, the pin 40
There is a possibility that inconveniences such as permanent deformation such as elongation or bending of the joint surfaces 14 and 24 in the vicinity thereof may occur.

In the excavator 1, the magnitude of the axial force applied to the connecting pin 40 during excavation is measured, and operating conditions are determined so as not to be excessive. Specifically, FIG.
A strain gauge 46 is attached to the pin 40 as shown in FIG. Pin 40
Is in contact with the inside of the elongated hole 40a of the joint surfaces 14 and 24, so that a shallow concave portion (not shown) is formed in a part of the outer peripheral surface.
Is formed, and the strain gauge 46 is attached to the concave portion to avoid contact with the elongated hole 40a. Strain gauge 4
6 detects the distortion of the pin 40, the control panel 51 multiplies the detection signal by the elastic coefficient of the pin 40, etc.
Calculate a stress of 0. The so-called axial force (tensile force) is obtained by multiplying this stress by the cross-sectional area of the pin 40. In the illustrated case, the tensile stress σ _P is calculated for two places on the pin 40 as described above. Is treated as axial force as it is.

The control panel 51 controls various operating conditions of the excavator 1, and as shown in FIG.
.21 (the hydraulic motor 12a)
22a), the shield jack 31, and the middle bending jacks 18 and 28 (each of the hydraulic devices), and operate the respective rotation speed, extension speed (that is, excavation speed), and extension amount. As described above, the center bending of the excavator 1 is realized by providing a difference between the extension amounts of the plurality of center bending jacks 18 and 28 for each of the trunks 10 and 20.
By manipulating the amount of elongation, the angle of the middle fold can be arbitrarily determined. Such a control panel 51 has a pin 40
The output of the above strain gauge 46 is input, and the axial force of the pin 40 is displayed, and the above operating conditions are operated so as not to be excessive.

When the folding angle is the same, the cutter 1
The lower the rotation speed of the excavator 1, the higher the excavation speed of the excavator 1, the greater the propulsive force for excavation, and therefore the greater the force for rolling the excavator 1, so that the axial force generated on the connecting pin 40 is naturally growing. However, according to the investigation by the inventors of the excavator 1 and the like in which the strain gauges 46 and the like are arranged as described above, when the rotation speed and the excavation speed are the same, the difference in the angle of the middle bending, that is, the trunk 10・ 2
The greater the angle between the zeros, the greater the axial force of the pin 40.

FIG. 4 and FIG. 5 are data showing the results of the investigation by the inventors. The two graphs show the axial force σ _P (the above-described tensile stress) of the connecting pin 40 and the bending angles θ ₁ and θ _{2 of the} body portions 10 and 20 measured on the vertical axis, respectively, at the same time. The angles θ ₁ and θ ₂ are, for example, as shown in FIG. 2, the upper and lower axes G of the rear trunk 30 having a figure-eight cross section.
₁・ G ₂ front extension line
20 are the angles formed by the center lines F ₁ and F ₂ , and the angle θ between the trunks is represented by θ = θ ₁ + θ ₂ .

FIG. 4 and FIG. 5 show that the angle θ (= θ
_It can be seen that the axial force σ _P increases as ₁ + θ ₂ ) increases. The axial force σ _p is affected not only by the operating conditions of the excavator 1 but also by the soil quality of the excavated part, etc. When the soil quality changes, the excavation speed slightly changes. When the angle θ is large in the first half of the section (left side in both figures), the axial force σ _p is also large. In addition, according to the same investigation, even if the thrust of the excavator 1 by the shield jacks 31 (all of them) is about 20 tons,
It has also been found that a maximum of about 200 tons of axial force acts on the connecting pin 40.

In the shield machine 1, as described above, the axial force acting on the connecting pin 40 is measured and the operating conditions are controlled so that the axial force does not become excessive. No undesired deformation of 24 occurs. For example, if the axial force exceeds a certain level, a) If the tunnel path (linear) is strictly determined and cannot be changed, lower the excavation speed while maintaining the angle of the middle bend (or rotate the cutter). B) When the linearity can be changed to some extent, the axial force is reduced by changing the angle (the above angle θ) (and possibly the excavation speed, etc.) Good. The ability to operate the excavator 1 in this manner leads to maximizing the performance of the excavator 1 and smoothly proceeding with excavation of the tunnel. If the axial force is expected to be small because accurate grasping is not possible, the pin 40 and the like may be deformed by a large axial force, which may hinder subsequent excavation. If the priority is given to safety too much, there is a possibility that the ability of the excavator 1 may not be fully drawn out, but if the axial force can be grasped as described above, any of such disadvantages can be avoided. . It goes without saying that the data on the measured axial force can be used to improve the design of the shield machine and the operation method (that is, the shield method) in the future.

FIG. 6 is a schematic diagram showing the distribution of the pressure (earth pressure, ie, the pressure of earth and sand) acting on the trunks 10 and 20. FIG. 7 shows a survey result (oscillograph) in which the excavation distance is plotted on the horizontal axis and the earth pressure is plotted on the vertical axis. In the shield machine 1 shown in FIG. 1 and the like, a strain gauge is attached to the connection pin 40 as described above, and pressure sensors (not shown) are experimentally provided at a number of positions on the side surfaces of the body portions 10 and 20. Attachment was performed, and the axial force of the pin 40 was measured through them. As the pressure sensor, for example, a piezoelectric element made of ceramics or quartz is preferable because of its excellent wear resistance. By arranging such a sensor so as not to protrude from the side surfaces of the body parts 10 and 20 as much as possible, wear due to contact with earth and sand or the like is suppressed, and long-term use is possible.

The axial force of the pin 40 can be obtained by measuring the pressure acting on the side surfaces of the body portions 10 and 20 because the axial force is mechanically balanced with the pressure acting on the side surfaces. Because it is decided. For example, torso 1
Assuming that the pressure is distributed as shown in FIG. 6 on the side surface of 0.22, the axial force P (tensile force; product of tensile stress σ _P and cross-sectional area of pin 40) acting on connecting pin 40 at that time is as follows. Theoretically, it is obtained according to the following equation 1.

(Equation 1) However, what is particularly important in the above pressure distribution is the pressure on the surface of the portion (the middle portion in FIG. 6) inside each of the center lines F ₁ and F ₂ of the two body portions 10 and 20. It is. This is because the pressure in the portions outside the center lines F ₁ and F ₂ (upper quarter and lower quarter in FIG. 6) causes the body portions 10 and 20 to bend in the middle, and the excavator 1 Even when rolling, the change is small, and even if the change is made, the pressure generally balances between the upper and lower sides (that is, between the trunks 10 and 20). This is because they act in a direction in which the pins 14 and 24 are separated from each other to produce an axial force of the pin 40. Therefore, one point 10A was taken as the inner part as shown in FIG. 6, and the pressure _pn1 there was measured at the same time as the investigations shown in FIGS. FIG. 7 shows the result. If FIG. 7 is compared with the previous FIG. 4 (the horizontal axis of both figures is common because they are measured simultaneously), the axial force σ _p of the pin 40 has a strong correlation with the pressure _pn1. You can be sure. Therefore,
Thus, the pressure at one point 10A (or the center line F _1.
Measuring the pressures p _n1 and p _n2 ) in the part inside F ₂ ,
Alternatively, if the pressure distribution on all the side surfaces of the body parts 10 and 20 is measured, the axial force of the pin 40 can be known from the result by an appropriate conversion means (not shown). Then, the axial force of the pin 40 can be known without using direct measurement. As described above, an embodiment has been described, but the invention according to the application is not limited to the above embodiment. For example, when the shield machine is not connected to the rear trunk 30 shown in FIG. 1 or the like behind the trunk, or when there are a plurality of connecting pins between the trunks instead of one, The invention can be carried out also when the number of is three or more. Of course, it is also possible to use something other than the strain gauge as the means for measuring the axial force of the pin. Also, the means for bending the body part in the middle is not limited to the illustrated middle bending jacks 18 and 28. As an example, the joint surfaces 14 and 24 of the trunks 10 and 20 are connected by a hydraulic cylinder or the like arranged to the left and right (that is, the direction of the swing of the trunks 10 and 20), and the cylinder is expanded and contracted. It is also possible to take a measure such that the body portions 10 and 20 are bent in the middle by doing so.

According to the shield method of the first aspect, a tunnel having a cross-section in which a plurality of circles are connected can be excavated at once, and the positional relationship between the circular portions can be changed by rolling the shield machine. . During the rolling, the axial force of the pin for connecting the trunks of the excavator is measured, and the operating conditions of the excavator are determined so that the axial force does not become excessive. Therefore, the following advantages are provided. 1) Since undesired permanent deformation or the like does not occur on the pins and the joint surfaces, the tunnel machine can be smoothly rolled and the tunnel excavation can always be performed smoothly. 2) The ability of the excavator can be maximized within the range where the pins are not permanently deformed, and tunnel excavation can be promoted more efficiently than ever. 3) Workers do not need to frequently check the pins and their surroundings, so the number of workers can be reduced. 4) Because it is possible to grasp the load of the pin, which was previously unknown,
Manufacturing waste can be eliminated in the subsequent shield machine. In the shield method according to the second aspect, the axial force of the pin is known by measuring the pressure acting on the side surface of each body, thereby obtaining the advantages 1) to 4). Therefore, this method is suitable when it is difficult to measure the axial force of the pin. Claim 3
The shield machine described in the above can smoothly and automatically implement the shield method described in the first aspect. Therefore, the advantages of the above 1) to 4) are also brought.
In general, there is no fear that the configuration of the control unit is particularly complicated. The shield machine according to the fourth aspect measures the pressure acting on the side surface of each body using a pressure sensor and a conversion means instead of measuring the axial force of the pin. In addition to providing the above advantages 1) to 4), it is also possible to cope with cases where it is difficult to directly measure the axial force of the pin.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of a control device together with a shield machine 1;

FIG. 2 is a plan view of the shield machine 1 in the operation state of FIG.

FIG. 3A is a longitudinal sectional view showing the structure of the shield machine 1 and FIG. 3B is a front view thereof.

FIG. 4 is data showing the axial force of the connection pin 40 between the trunks actually measured in the shield machine 1 during excavation, the vertical axis represents the axial force of the pin 40, and the horizontal axis represents the excavation distance.

5 is a diagram showing actual measurement data of the shield machine 1 during excavation, in which the vertical axis represents the angle at which each body part is bent, and the horizontal axis represents the same excavation distance as the horizontal axis in FIG.

FIG. 6 is a schematic diagram showing a distribution of pressure acting on the side surfaces of the trunks 10 and 20.

7 is a diagram showing actual measurement data of the shield machine 1 during excavation, in which the vertical axis represents pressure acting on one point on the side surface of the body 10, and the horizontal axis represents the same excavation distance as the horizontal axis in FIG. .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Shield excavator 10.20 Body 11.21 Rotary cutter 14.24 Joining surface 18.28 Center bending jack (angle changing means between body parts) 31 Shield jack (propulsion means) 40 pin 46 Strain gauge (shaft) Force control means) 51 Control panel θ ₁ , θ ₂

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hirofumi Kyoriki 1-3-1, Higashikawasaki-cho, Chuo-ku, Kobe-shi, Hyogo Kawasaki Heavy Industries, Ltd. Kobe Head Office (72) Inventor Muneo Yoshimura Motoichi Akasaka, Minato-ku, Tokyo No. 2-7 Kashima Construction Co., Ltd. (72) Inventor Yukihiko Hizawa 1-3-15 Awaza, Nishi-ku, Osaka-shi, Osaka Kashima Construction Co., Ltd.Kansai Branch (72) Inventor Yasuhiro Ueki, Minato-ku, Tokyo 1-3-8 Akasaka Kashima Construction Co., Ltd. Tokyo Branch (56) References JP-A-5-93498 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 9/08 E21D 9/06 301

Claims (4)

(57) [Claims] 1. A plurality of circular bodies each having a plurality of circular bodies using a shield excavator in which a plurality of body parts each having a rotary cutter in front thereof are connected by pins so as to be able to change an angle between the body parts while partially joining each side surface. A shield construction method for excavating a tunnel having a continuous cross section, wherein during the excavation, the axial force acting on the pins is measured, and one or more of the angle between the trunks, the rotation speed of the cutter, and the excavation speed are determined. A shield method characterized by operating so that the axial force does not become excessive. 2. The pressure acting on the side of each body is measured,
The shield method according to claim 1, wherein the axial force of the pin is known by converting the pressure. 3. A shield machine wherein a plurality of body portions each having a rotary cutter in front thereof are connected by pins so as to be able to change an angle between the body portions while partially joining each side surface, A shield excavator wherein an axial force measuring means is attached to a pin, and the measuring means is connected to at least one control unit among an angle changing means between body parts, a rotation driving means of a cutter and a propulsion means. . 4. A pressure sensor is attached to a side surface of each body, and conversion means for obtaining an axial force of the pin from a detected value of the sensor is provided in the machine, and these are used as the means for measuring the axial force. 3. The shield machine described in 3.