JP5960784B2 - Open shield method - Google Patents

Description

  The present invention relates to an open shield method for constructing underground structures such as water and sewage systems and underground passages in an urban area.

  The open shield method is an efficient method that takes advantage of the open cut method (open cut method) and the shield method. Of these open shield methods, the body of the open shield machine 1 is divided into multiple parts in the longitudinal direction. The self-propelled open shield machine 1 that takes the reaction force from other divided blocks and moves forward in the same manner as the ESA method (ENDLESS SELF ADVANCING METHOD) “Infinite self-propelled forward construction method” is the following patent Proposed as shown in the literature.

The ESA method (ENDLESS SELF ADVANCING METHOD) “infinite self-propelled forward method” is similar in principle to the movement of a scale insect, and the head is advanced with the tail fixed (reaction force). Next, the head is fixed (reaction force) and the tail moves. This is repeated to advance, and a plurality of (three or more) box culverts are connected with PC steel wires, and hydraulic jacks are installed between and at the end of each box culvert to constitute an ESA facility. The jack pressure is transmitted to each box culvert. When a single box culvert is propelled, it is sequentially propelled one box at a time as the reaction force resistance is the friction resistance force caused by the earth pressure and weight of the other plurality of box culverts.
JP 2000-64779 A JP 2002-349187 A

  As shown in FIGS. 2, 3, and 4, the open shield machine 1 divides the machine body into a plurality of parts in the front-rear direction. In this embodiment, the front part 1 d having a blade edge 11 at the tip, the middle part 1e and the tail portion 1c on which the concrete box 4 is suspended, and the first propulsion jack 12 is interposed between the front portion 1d and the middle portion 1e, and between the middle portion 1e and the tail portion 1c. The second propulsion jack 13 and the third propulsion jack 14 are disposed between the front portion 1d and the tail portion 1c, respectively. A pin jack is used for these propulsion jacks 12, 13, and 14.

  In the example of Patent Document 2, the body width of the front portion 1d, middle portion 1e, and tail portion 1c is such that the middle portion 1e is smaller than the front portion 1d and the tail portion 1c is smaller than the middle portion 1e. It is formed so that it gradually decreases as it goes backward with respect to the propulsion direction.

  A steel friction cutter 15 divided into a plurality of parts is provided at the bottom of the front part 1d, and a friction cutter jack 19 for advancing the friction cutter 15 is provided at the bottom of the front part 1d.

  On the side of the middle portion 1e, an outkey (slit) 16 is provided so as to protrude from the side natural ground and penetrate into the natural ground, and an outkey jack 17 for obtaining a reaction force from the natural ground is disposed.

  Further, a stopper jack 18 for obtaining a reaction force from the rear concrete box 4 is disposed at the rear part of the middle part 1e.

  In the open shield method using such an open shield machine 1, the forward shield method of the open shield machine 1 first lays the concrete box 4 in the tail part 1c as a first step.

  Next, as a second step, the friction cutter jack 19 disposed at the bottom of the front portion 1d is extended to advance the friction cutter 15.

  Thereafter, as a third step, the first propulsion jack 12 is extended, and only the front portion 1 d is advanced by the stroke of the first propulsion jack 12. At this time, the first propulsion jack 12 extends with the reaction force that is the frictional resistance caused by the weight of the rear middle part 1e and tail part 1c and earth pressure.

  In this case, since the front portion 1d moves forward on the friction cutter 15 advanced in the previous step, both of them become sliding friction between the steel friction cutter 15 and the bottom portion of the front portion 1d, and the front portion 1d is used for excavation. The frictional resistance is small, and the front portion 1d can move forward in a sliding manner. When the front portion 1d is dug, the friction cutter jack 19 is set in a relief state and returned at the same speed as the propulsion speed of the front portion 1d.

  In addition, when the front part 1d moves forward, frictional resistance is also generated between the front part and the ground, so if the reaction force is insufficient, the outkey jack 17 disposed in the middle part 1e is extended. The outkey (slit) 16 projects over the side ground and penetrates into the ground. Thereby, the middle part 1e is fixed to the natural ground, and the reaction force can be increased.

  When the reaction force is still insufficient with the outkey (slit) 16, the stopper jack 18 is extended rearward and the tip is brought into contact with the concrete box 4, so that the middle portion 1e and the tail when the front portion 1d moves forward. The part 1c is prevented from returning to the rear, and a deficient reaction force is obtained from the concrete box 4. In this case, the stopper jack 18 is for obtaining the reaction force that is insufficient as described above from the concrete box 4 and is not propelled by the stopper jack 18.

  Next, as the fourth step, the second propulsion jack 13 is extended to advance the middle portion 1e toward the front portion 1d.

  When the middle portion 1e moves forward, the first propulsion jack 12 is set in a relief state and returned at the same speed as the propulsion speed of the middle portion 1e. Further, when the outkey jack 17 is used at the time of propulsion of the front portion 1d, this pullback is performed. And the amount of middle breakage can be secured by the extension stroke of the second propulsion jack 13, and the forward direction can be corrected.

  Further, the tail portion 1c is advanced by the second propulsion jack 13 and the third propulsion jack 14 as a fifth step. At this time, since the tail portion 1c is directly connected to the front portion 1d by the third propulsion jack 14, it can be easily retracted. Further, since the tail portion 1c is formed to be narrower than the middle portion 1e, no frictional resistance is generated between the tail portion 1c and the ground, and the second propulsion jack 13 and the third propulsion jack are not generated. The jack 14 has only to pull in its own weight of the tail portion 1c, and can be easily propelled.

  By repeating this process, a plurality of concrete boxes 4 are laid in columns.

  In this way, the front part 1d, the middle part 1e, and the tail part 1c, which are each divided body block, are individually taken in the same manner as the ESA method by taking the reaction force from the other divided bodies by the extension and traction of the propulsion jack. Self-run and move forward.

  Therefore, not only can each divided body change direction easily and curve construction is possible, it is basically unnecessary to apply a reaction force to the concrete box 4 at the rear, and a reaction wall is installed. Since the start pit is also unnecessary, construction is easy and the construction period can be shortened. In particular, the advantage of using a self-propelled open shield machine is that the conventional open shield construction method and open shield machine require a reaction wall to take a reaction force to start. Must be formed. In addition, the concrete box 4 moves forward with a reaction force on the concrete box 4 left in the ground, and the concrete box 4 becomes a reaction body for the advance of the open shield machine 1 and receives the thrust of the jack, so that cracks are not generated. Easy to enter and requires strength. The occurrence of this crack is likely to occur when an unbalanced external force is applied to the concrete box 4 due to different degrees of extension of the propulsion jack on the left and right when performing curved construction. As a result, it is possible to solve the problem of increasing the amount of reinforcing bars and covering the surface with a steel plate.

  In Patent Document 2, when the middle part and the tail part are advanced, the friction resistance can be reduced between the ground part of the side part and the digging can be easily carried out. However, the self-propelled type of the conventional open shield machine is The blade edge resistance at the time of propulsion of the first block, which is the front part, is large, the propulsion of the front part requires a large thrust, and depending on the soil conditions, the front part cannot be advanced, or the middle part and the tail part The second block and the third block may move backward.

  In Patent Document 2, the friction of the front portion is reduced by using a friction cutter. However, only the bottom portion is considered, which is not sufficient. When the front portion moves forward, frictional resistance is also generated between the ground and the side.

  Therefore, the reaction force of the middle part may be insufficient. In this case, it is necessary to provide an outkey jack and an outkey in the middle part.

  Furthermore, when the reaction force is still insufficient with the out key, it is necessary to dispose a stopper jack, which is extended rearward and the tip is brought into contact with the concrete box. And the tail part is prevented from returning backward.

  If such an outkey jack, outkey, or stopper jack must be arranged, it is cumbersome and the construction procedure is complicated.

  The present invention eliminates the inconvenience of the conventional example, and the front shield, middle part, tail part three-part block or two-part block constitutes the body of the open shield machine, and the reaction force from other part blocks It is necessary for resistance even when the peripheral surface friction cannot be obtained sufficiently when moving forward independently by the same method as the ESA method (ENDLESS SELF ADVANCING METHOD) The minimum auxiliary reaction force can be obtained by the propulsion auxiliary jack, and the necessity of the propulsion auxiliary jack can be mechanically judged and automatically operated, so that no unnecessary load is applied to the reaction force body. The purpose is to provide an open shield method that can be used for construction.

In order to achieve the above object, according to the present invention, the airframe has first, second, and third divided body blocks as a front portion, a middle portion, and a tail portion, and the front portion and the middle portion are propulsion jacks. Use the open shield machine that connects with the first propulsion / traction jack as the first, and connects the middle part and the tail with the second propulsion / traction jack as the propulsion jack, the front part is the middle part and the tail part The middle part extends with the reaction force on the front part and the tail part by the first propulsion / traction jack and the second propulsion / traction jack. The tail part is opened by actuating the second propulsion / traction jack and pulling forward with the second propulsion / traction jack as a reaction force of the split block of the front part and the middle part. In Rudo method, middle portion, between the tail portion, the propulsion jacks be obtained from the reaction force member is provided which also serves as a laying foundation of concrete box-body forming the propulsion reaction force under a concrete box making bodies in the concrete a box body installed propulsion A pressure gauge is installed in the hydraulic system that operates the first propulsion / traction jack and the second propulsion / traction jack, which are jacks, and the pressure detected by the pressure gauge is taken into a PC (personal computer) as a signal and input to the PC in advance. When the propulsion force of the shield machine obtained by the specifications of the propulsion jack and the number of units used falls below a certain value previously input to the PC, a control signal is issued, and the operation panel for the propulsion auxiliary jack and its pump the driving force for this propulsion jacks added by opening the electromagnetic valve provided in the bypass line between, obtained by the specification and use the number of propulsion jacks Shi If the propulsion power of the machine exceeds the constant value previously input to the PC, a control signal is issued and the solenoid valve provided in the bypass line between the operation panel for the propulsion auxiliary jack and its pump is closed. Therefore, the gist is not to operate the propulsion auxiliary jack .

  According to the first aspect of the present invention, the necessity of the propulsion auxiliary jack can be mechanically determined by using the PC and the automatic operation can be automatically performed. Construction can be done without applying unnecessary load. Thus, even when the excavation resistance is insufficient, the auxiliary reaction force is automatically obtained, so that construction can be performed without delay.

In addition, the propulsion reaction force of the propulsion auxiliary jack is not obtained directly from the concrete box, and since there is no jack thrust applied to the concrete box, there is no risk of damaging the concrete box. In particular, there is no need to apply a reaction force to the concrete box at the back, and since there is no need for a start pit with a reaction wall, the construction of the self-propelled forward-type open shield method can be simplified and the construction period can be shortened. The benefits are not compromised.

Further, the propulsion auxiliary jack is always applied to the reaction force body in a state close to no load, and when the digging resistance is insufficient, the reaction force body is supported.

  As described above, the open shield construction method according to the present invention comprises an open shield machine body composed of a three-part block or a two-part block of a front part, a middle part, and a tail part. When using the ESA method (ENDLESS SELF ADVANCING METHOD) "Infinite self-propelled advance method" to advance by individual self-propelled method, even if the peripheral surface friction is not sufficiently obtained, The minimum necessary reaction force can be obtained by the propulsion auxiliary jack, and the necessity of the propulsion auxiliary jack can be mechanically judged and automatically operated, so an unnecessary load is applied to the reaction force body. It can be constructed without

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view of an embodiment of the open shield method of the present invention, in which the same components as those in FIGS.

  The basic structure of the open shield machine 1 to be used is the same as that of the conventional example. The front end is formed as a blade edge, and the propulsion jacks are arranged in the vertical direction near the center or near the rear end of the side wall plate.

  In this embodiment, the open shield machine 1 divides the machine body into a plurality of parts in the front-rear direction, and includes a front part 1d having a blade edge 11 at the tip, a middle part 1e, and a tail part 1c on which the concrete box 4 is suspended. Divided into 3 blocks.

  A first propulsion / traction jack 12 is provided between a front part 1d as a first divided body block and a middle part 1e as a second divided body block, and a tail as a middle part 1e and a third divided body block. A second propulsion / traction jack 13 is disposed between each portion 1c. For these propulsion / traction jacks 12 and 13 (hereinafter referred to as “propulsion jack A”), pin jacks whose ends are pivotally mounted are used.

  In the present invention, the propulsion auxiliary jack 19 is provided between the middle portion 1e and the tail portion 1c so as to straddle the middle portion 1e and the tail portion 1c.

  In the tail portion 1c, the propulsion auxiliary jack 19 is installed on the front side of the place where the concrete box 4 is suspended, with its extension rod facing rearward.

  In the figure, 21 is a hydraulic pump for driving the first propulsion / traction jack 12 and the second propulsion / traction jack 13 (propulsion jack A), and 22 is its operation panel. A pressure gauge 23 is provided in the hydraulic system, and the pressure detection signal is taken into a PC (personal computer) 25 via the converter 24.

  In the PC (personal computer) 25, the specification of the propulsion jack A, the numerical value related to the number of units used, the digging resistance for operating the propulsion auxiliary jack 19 and the like are input. Means for comparing a proper set value, which is a proper propulsive force based on the actual propulsive force measured by the pressure gauge 23, is formed.

  In the figure, 27 is a hydraulic pump of the propulsion auxiliary jack 19, 28 is an operation panel, and 29 is an electromagnetic valve provided in a bypass line between the operation panel 28 of the propulsion auxiliary jack 19 and the hydraulic pump 27. A control signal for the electromagnetic valve 29 to be operated is sent from the PC (personal computer) 25 via the converter 26.

  The open shield construction method of the present invention using the open shield machine 1 will be described. Although the illustration of the first start after forming the start pit is omitted, a part of the retaining wall of the start pit is partially mirrored. Accordingly, the ground is improved in the front part of the starting pit by chemical solution injection, etc., the reaction wall is installed, and the propulsion / traction jack A is propelled through the struts as appropriate.

  If the open shield machine 1 is dug to secure a space for laying the concrete box 4 in the tail portion 1c, the reaction body 30 is constructed below the laying space of the concrete box 4.

  This reaction force body 30 also serves as a foundation for laying the concrete box 4, and crushed stone is spread in the tail portion 1c, and a concrete plate is laid on the box foundation. The concrete plate may be a form made of on-site cast concrete, but a PC plate (precast concrete plate) is used.

  The concrete board is laid so as to be connected to the previously laid concrete board, and a new concrete box 4 is set on the concrete board, and the propulsion jack is extended by using the continuous body of the concrete board as a reaction force. The shield machine shall be moved forward.

Table 1 below shows the propulsion cycle of the open shield machine 1.

  In the forward method of the open shield machine 1, as a first step, the propulsion / traction jack 12 is expanded / contracted (extension) as the propulsion of the front portion 1 d using the earth pressure and the own weight of the middle portion 1 e and the tail portion 1 c as reaction forces Thus, the front portion 1d is propelled. In addition, the propulsion auxiliary jack 19 can be fixed and interposed as a back prevention and auxiliary reaction force.

  As the second step, as the middle part 1e is propelled, the propulsion / traction jack 12 and the propulsion / traction jack 13 are expanded and contracted using the earth pressure and weight of the front part 1d and tail part 1c as reaction force The propulsion / traction jack 13 is extended) to propel the middle portion 1e. The propulsion auxiliary jack 19 can be fixed and interposed as a back prevention and auxiliary reaction force.

  As the third step, the tail portion 1c is propelled by expanding / contracting (reducing) the propulsion / traction jack 13 with the earth pressure and weight of the front portion 1d and the middle portion 1e as reaction forces as propulsion of the tail portion 1c. The propulsion auxiliary jack 19 can be fixed and interposed as a back prevention and auxiliary reaction force.

  The first to third steps are repeated, and the open shield machine 1 for one box is dug. A foundation crushed stone is spread and ground in a similar tail portion 1c, and a concrete plate is installed to build a foundation.

  The concrete box 4 is installed from behind the open shield machine 1 with a crane.

  In this way, a reaction force is obtained from the passive earth pressure of the starting shaft at the initial stage, and a reaction force is obtained from the peripheral frictional resistance of the open shield machine 1 at the stage of excavation to some extent.

  When sufficient circumferential friction is obtained, the minimum auxiliary reaction force required for the excavation resistance is obtained from the propulsion auxiliary jack 19.

  In the PC (personal computer) 25, the pressure detected by the pressure gauge is taken as a signal, and the propulsive force of the shield machine obtained by the specification of the propulsion jack A and the number of units used previously input to the PC 25 is input to the PC in advance. When it falls below a certain fixed value, a control signal is issued, the electromagnetic valve 29 is opened, and the propulsive force of the propulsion auxiliary jack 19 is applied.

  When the propulsion force of the shield machine obtained by the specification of the propulsion jack and the number of units used exceeds a certain value previously input to the PC 25, a control signal is issued, the propulsion auxiliary jack is closed by closing the solenoid valve 29. 19 is not operated.

It is explanatory drawing which shows one Embodiment of the open shield construction method of this invention. It is a top view of a prior art example. It is a vertical side view of a prior art example. It is a longitudinal front view partly cut away of the conventional example.

DESCRIPTION OF SYMBOLS 1 ... Open shield machine 1c ... Tail part 1d ... Front part 1e ... Middle part 4 ... Concrete box 11 ... Blade 12 ... First propulsion / traction jack 13 ... Second propulsion / traction jack 15 ... Friction cutter

16 ... Out key 17 ... Out key jack 18 ... Stopper jack 19 ... Propulsion auxiliary jack 21 ... Hydraulic pump 22 ... Control panel 23 ... Pressure gauge 24 ... Converter 25 ... PC (personal computer)
26 ... Converter 27 ... Hydraulic pump 28 ... Operation panel 29 ... Solenoid valve 30 ... Reaction body

Claims (1)

The airframe is made up of the first, second, and third divided blocks that will be the front, middle, and tail, and the front and middle are connected by the first propulsion / traction jack as a propulsion jack. The front part is moved forward with the frictional resistance due to the weight of the middle part and the tail part and earth pressure as the reaction force. The middle part is advanced by extending the reaction force against the front part and the tail part with the first propulsion / traction jack and the second propulsion / traction jack, and the tail part is the second propulsion / traction in the open shield method for advancing towing forward the divided body blocks of the front portion and the middle portion by operating the jack in the second promotion and traction jack as reaction force, middle portion, between the tail portion, Susumu reaction force of propulsion jacks be obtained from the reaction force member is provided which also serves as a laying foundation of concrete box-body forming under concrete box making bodies in the concrete a box body installation, the first propulsion-traction jack is the driving jack, the A pressure gauge is installed in the hydraulic system that operates the 2 propulsion / traction jacks, the pressure detected by the pressure gauge is taken into a PC (personal computer) as a signal, and obtained according to the specifications and number of propulsion jacks that have been input to the PC in advance. When the propulsive force of the shielded machine falls below a certain value previously input to the PC, a control signal is issued, and the solenoid valve provided in the bypass line between the operation panel for the propulsion auxiliary jack and its pump is opened. the driving force for this propulsion jacks addition, certain of propulsion of the shield machine obtained by the specification and use the number of propulsion jack had been input in advance to the PC It issues a control signal if they exceed the open shield tunneling, characterized in that not operated propulsion jacks closes the electromagnetic valve provided in the bypass line between the control panel and its pump for propulsion jacks.

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