JP4206054B2 - Shield drilling assembly simultaneous construction method - Google Patents

Description

The present invention relates to a method for assembling segments in a shield construction method, and more particularly to a shield excavation assembly simultaneous construction method using a trapezoidal segment so that the assembly can be performed simultaneously with the excavation of a shield excavator .

As a technique for performing segment assembly simultaneously with excavation, for example, a technique described in the following patent document is known.
<Patent Document 1 (Patent No. 3104955)>
During jacking, the number of jacks necessary for the set propulsion force of the shield body is set in advance, while the bending moment of the shield body is obtained from the moments in the pitching direction and yawing direction. Refill the jacks, and replace the other jacks except the replacement jack group P4 with the number of load side jack groups P1 and the remaining jacks required for the set propulsion force on both sides of the replacement jack group P4. The control-side jack groups P2 and P3 are divided into control pressures applied to the load-side jack groups P1 and the control-side jack groups P2 and P3 based on the set propulsive force and the moments in the pitching direction and yawing direction. Set the pressure, and then assemble the segment while changing the refill jack sequentially and push the shield body .

  However, according to this, it is necessary to divide the jacks into groups, and individual jack pressures cannot be set freely. For this reason, the jack moment cannot be set efficiently, and the shield machine equipped with the jack of the same ability has low posture correcting ability.

<Patent Document 2 (JP-A-8-199972)>
The front torso and the rear torso where the segments are assembled have a telescopic structure that can be slid in the front-rear direction. The stroke of the shield jack attached to the front trunk is longer than the segment width for two rings, and in the sharp curve section, the front trunk and the rear trunk are shortened and the shield machine body is shortened for excavation and segment assembly. Alternately, in a straight or gentle curve section, stretch the front and rear torso parts and lengthen the shield machine. By excavating and assembling the segment by assembling the segment in the part corresponding to the remaining shield jack while propelling the machine Carried out at the same time.

  However, this complicates the structure of the shield machine and increases the equipment cost.

  On the other hand, as a technique for assembling a segment ring by assembling only a trapezoidal segment, there are those described in Patent Document 3 (Patent No. 2835929), Patent Document (Patent No. 3276579), and the like.

  However, in the segment assembling method of Patent Document 3, the long side of one trapezoidal segment is fixed to the end face of the completion ring, and then a parallelogram is formed by two segments, and this is attached to a single segment. Similarly, two segments form a parallelogram and are attached adjacent to the preceding segment. Finally, one trapezoidal segment is used to cover the remaining space. It is not a simultaneous construction method in which excavation of the excavator and segment assembly are performed in parallel.

In the segment assembling method of Patent Document 4, a large trapezoid segment having a long arc length and a small trapezoid segment having a short arc length are used, and the small trapezoid segment is transported to an installation location between previously installed large trapezoid segments. At the same time, the ring joint surface side of the trapezoid of the trapezoid of the small trapezoid segment is moved in the centrifugal direction of the tunnel with a part of it entering between the large trapezoid segments installed in advance, that is, the tunnel shaft This is a normal assembly method designed to assemble the small trapezoidal segment by inserting it in the centrifugal direction instead of the direction, and is also a normal assembly method intended to prevent the drilling stroke from becoming long. It's not the law.
Japanese Patent No. 3104955 JP-A-8-199972 Japanese Patent No. 2835929 Japanese Patent No. 3276579

An object of the present invention, can be efficiently co-construction the assembled using the same trapezoidal segments in parallel with the excavation of the shield machine, moreover shortening the excavation assembly cycle, capable of stable posture control during simultaneous construction shield It is to provide a method for simultaneous construction of excavation assembly .

The present invention is a shield excavation assembly simultaneous construction method comprising a plurality of jacks arranged at equal intervals on the same circumference and sequentially assembling segments in parallel with the excavation of the shield excavator by these jacks. , a plurality of trapezoidal segments short side has a forward-facing front facing excavation, while sequentially assembled every other by circumferentially jack corresponding to the segment in parallel with this, the pressure of the jack which does not correspond to the segment The primary trapping process in which the shield excavator is excavated while adjusting, and a plurality of trapezoidal segments with the long side facing in the reverse direction facing the front of the excavation , by the jacks corresponding to the segments, the forward trapezoids that are alternated Secondary inserted between the segments with the shield machine stopped in the axial direction and assembled with the forward trapezoidal segment Characterized in that a standing step.

In such simultaneous construction, there is no problem with a long excavation stroke, which is a problem when a trapezoidal segment is used.
That is, in the simultaneous construction, since the assembly is performed during the propulsion, an extra stroke is always required. The start of assembling the first segment requires more than the segment width, and when the assembly is performed from there, the stroke increases as the number of assembling segments increases due to the propulsion of the shield machine.
For example, when digging at 50 mm per minute, assuming that it takes 4 minutes to assemble one segment, it is propelled 600 mm by 3 segments.
Therefore, when assembling three segments, the above-mentioned marginal stroke is always necessary, and the elongation of the stroke for inserting the trapezoidal segment is not a problem at all.

In the primary assembly process, the jack corresponding to the forward trapezoidal segment is pulled back after depressurization, and during that time, the other segment of the jack is propelled to the required stroke while taking the reaction force with the existing segment ring and controlling the posture to assemble the segment . simultaneously pull back the jack corresponding to the forward-facing trapezoidal segments assembled next after decompression, during which further promote while attitude control taking a reaction force in a forward direction trapezoidal segments assembled to the existing segment ring and above the other jack Then, the next forward trapezoidal segment is assembled, and at the same time , the jack corresponding to the forward trapezoidal segment to be assembled next is decompressed and then pulled back.

  The jack that takes the reaction force in the forward trapezoidal segment that has been assembled earlier is tuned to a lower pressure than the propulsion jack that takes the reaction force in the existing segment ring.

Pulling back the jack is the next step,
A jack moment calculating step of calculating a first jack moment M1 by a jack that is currently obtaining a thrust and calculating a second jack moment M2 by a jack excluding the jack to be pulled back before the jack to be pulled back is pulled back. When,
A thrust balance calculating step of calculating a thrust balance in which the first jack moment M1 and the second jack moment M2 are the same for a jack excluding the jack to be pulled back ;
A jack pulling back step of pulling back the jack to be pulled back while controlling the pressure of the jack according to the calculated thrust balance .

  In the jack pull-back step, the pressure may be gradually changed so that the time required for decompressing the jack to be pulled back and the time required for pressurizing other jacks are the same time.

  When adding a jack to be pulled back, pull back the added jack while keeping the jack that takes the reaction force in the forward-facing trapezoid segment assembled earlier at a lower pressure than the propulsion jack that takes the reaction force in the existing segment ring. .

  When propelling by adding a jack to be pulled back, the first jack moment M1 is the moment due to the jack that is actually gaining thrust, and the moment assumed when propelling by partially adding the jack to be pulled is the first. 2 is calculated as a jack moment M2.

  When returning a part of the jack that has been pulled back, pressurize the jack and depressurize the other jacks to maintain the thrust balance.

  The forward trapezoid segment and the reverse trapezoid segment use substantially the same segment.

The present invention has the following effects.
(1) During excavation, half of the segments of one segment ring can be assembled in parallel, so that the assembly process is more efficient and faster than in the past, and the construction cost and construction period can be reduced.
(2) Since the trapezoidal segment can be obtained by equally dividing all segments, not only the cost of the segment is reduced, but also the workability of segment management and handling is improved.
(3) Since the length of the shield machine can be increased by increasing the length of the shield machine by an amount corresponding to the segment width, it can be applied to general construction including a small start shaft and a sharp curve.
(4) Since the assembly positions of the segments are dispersed, there is no uneven load due to the propulsion jack, and the moment is not biased in one direction. Therefore, there is little influence on quality, such as a deformation of a shield machine and a segment crack. It can also handle high water pressure and sharp curve construction.
(5) The speed is increased moderately, the labor burden on the worker is small, and the work can be performed safely.
(6) Although the shield machine length is longer than the conventional shield machine, if it is limited to simultaneous construction, the machine length will be shorter than other shield machines, and sharp curve construction will be possible with the provision of a middle folding mechanism.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  In FIG. 1 (A), the shield machine 1 has a front body portion 1A having a cutter 2 on the front surface, and the direction of the rear body portion 1B that performs segment assembly inside can be freely changed by a middle folding mechanism 3. It can be done.

  As shown in FIG. 1 (B), the shield machine 1 is extended by the reaction force of all or a part of the n jacks 4 arranged at equal intervals on the same circumference. To be promoted.

  In the present invention, as shown in FIG. 3, the same trapezoid segment 5 in which one ring is equally divided into an arbitrary number is used, but the assembly is performed so that the directions of adjacent segments are alternately switched in one ring. Is assembled in two steps, a primary assembly step and a secondary assembly step.

  That is, in the primary assembling step, as shown in FIG. 3, every other trapezoidal segment 5 is assembled in the circumferential direction with the short side of the trapezoidal segment 5 in the forward direction facing the front of excavation (face side). The assembly is performed in parallel while digging the shield machine 1 as will be described later. However, the assembly order is free. Hereinafter, the forward-oriented trapezoidal segment is denoted by reference numeral 5a.

  In the secondary assembly process, as shown in FIG. 4, the direction of the trapezoid segment 5 is set to be opposite to the long side of the trapezoidal segment 5a toward the front of the digging (face side). Insert and assemble in the axial direction between. The assembly is performed with the shield machine 1 stopped. Also in this case, the assembly order is free. In the following, the trapezoidal segment in the reverse direction is denoted by reference numeral 5b.

  Next, specific examples of the primary assembly process and the secondary assembly process will be described in detail with reference to FIGS. In each of these drawings, (A) shows a group of jacks arranged in the circumferential direction of the shield machine 1 with numbers sequentially in the clockwise direction, and (B) shows the expansion / contraction state of the jack together with the segments. . A black circle in (A) represents a main jack that performs propulsion and attitude control of the shield machine 1 by controlling its pressure. This is referred to as a “propulsion jack” and is denoted by reference numeral 4a. . A white circle indicates a jack that is being pulled back and is being pulled back or has been pulled back, and is referred to as a “back jack” and is denoted by reference numeral 4b. The hatched circle represents an auxiliary jack that presses against the propulsion jack 4a at a low pressure (pushing against the previously assembled segment to provide propulsion assistance), and is referred to as a “low pressure jack”. 4c is attached.

<Primary assembly process>
As shown in FIG. 5, the reaction force is applied to the existing segment ring, and after reaching the first stroke ST1, the decompression of the 6th to 10th jacks corresponding to the assembly range of the first piece segment is started. During this time, the pressure of the other propulsion jack 4a is adjusted to maintain the moment of the shield machine 1.

M in FIG. 1B indicates the resultant action point of the XY coordinate system by the combined moment of the jack group 4 that is propelling the shield machine 1. Here, jack from first to n-th are arranged from the shield machine center O at the same radius R, the mounting angle of the i-th jack theta _i, for the thrust and P _i. Upon detection of this thrust P _i in a known manner, X component M _X of the synthesized jack moment following equation (1), Y component M _Y is given by equation (2).

  The jack to be pulled back is decompressed while controlling the pressure of the jack group so that the resultant force point M does not deviate from the resultant force ratio, that is, while maintaining a predetermined moment.

  As shown in FIG. 5, the 6th to 10th jacks 4b are pulled back after completion of the pressure reduction. During this time, the pressure of the propulsion jack 4a is adjusted to control the attitude of the shield machine 1. In this case, the first stroke ST1 is shorter than the front-rear width W of the segment 6.

  As shown in FIG. 6, when the 6th to 10th jacks are pulled back and the second stroke ST2 is secured, assembly of the forward segment 5a of the first piece is started in the assembly range.

  Simultaneously with the start of the assembly, the decompression of the jacks Nos. 22 to 24, 1 and 2 corresponding to the assembly range of the second piece is started while maintaining the moment. Also at this time, as described above, the jack to be pulled back is reduced while controlling the pressure of the jack group so that the resultant force point M does not deviate from the resultant force ratio, that is, while maintaining the predetermined moment. I will do it. After completion of decompression, the jacks 4b of Nos. 22-24, 1 and 2 are pulled back while controlling the posture.

  As shown in FIG. 7, after the assembly of the forward-facing segment 5a of the first piece is completed, the jacks 7 to 9 facing the end surface on the short side of the segment 5a are pressed against the segment 5a as a low-pressure jack 4c to propel it. Synchronize with the jack 4a.

  FIG. 2A shows the resultant action point of the XY coordinate system by the combined moment of the propulsion jack group that is propelling the shield machine 1 at this time, as in FIG. While controlling the pressure of the propulsion jack 4a so that the resultant force acting point does not deviate, the low pressure jack 4c is pressurized until a preset pressure is reached, and the low pressure propulsion is performed.

  As shown in FIG. 8, the assembly of the forward segment 5a of the second piece is started, and at the same time, the pressure reduction of the jacks No. 14-18 corresponding to the next assembly range is started while maintaining the moment. After completion of decompression, the jacks 4b of Nos. 14 to 18 are pulled back while controlling the posture.

  As shown in FIG. 9, after the assembly of the forward-facing segment 5a of the second piece is completed, the jacks Nos. 23, 24 and 1 facing the short side of the segment 5a are pressed against the segment 5a as a low-pressure jack 4c. , Synchronize with the propulsion jack 4a.

  FIG. 2B shows the resultant action point of the XY coordinate system by the combined moment of the jack group 4 that is propelling the shield machine 1 at this time, as in FIG. While controlling the pressure of the propulsion jack 4a shown in FIG. 9 so that the resultant force application point does not deviate, the newly added low-pressure jack 4c is pressurized until it reaches a preset pressure, and is propelled at a low pressure. .

  As shown in FIG. 10, the assembly of the forward-facing segment 5a of the third piece is started, and after completion of the assembly, the jacks 15 to 17 facing the end surface on the short side of the segment 5a are used as the low-pressure jack 4c. Press against segment 5a and synchronize with propulsion jack 4a to maintain moment. After the synchronization is completed, the low-pressure jack 4c is pressurized until it reaches a preset pressure in the same manner while controlling the pressure of the propulsion jack 4a, and the low-pressure propulsion is performed. When the third stroke ST3 is reached, the excavation is completed in the primary assembly process.

<Secondary assembly process>
As shown in FIG. 11, simultaneously with the completion of excavation, the 11th to 13th jacks corresponding to the next assembly range are pulled back and the fourth piece segment is assembled as the reverse segment 5b. After the assembly is completed, the jacks 10 to 14 are extended.

  As shown in FIG. 12, the 3rd to 5th jacks corresponding to the next assembly range are pulled back, and the fifth piece segment is assembled as the reverse segment 5b. After completion of the assembly, the jacks 2-6 are extended.

  As shown in FIG. 13, the 19th to 21st jacks corresponding to the next assembly range are pulled back, and the sixth piece segment is assembled as the reverse segment 5b. After completion of the assembly, the jacks 18 to 22 are extended to complete the assembly of one ring.

  FIG. 14 shows the relationship between the jack division and the jack arrangement when the segment is divided into six and the number of jacks is 24 as described above. In this case, the number of bolts between rings is 24.

Next, jack pressure control will be described.
If the pressure control for the jack group that is not pulled back is performed as follows, the posture control can be performed more efficiently.

  Select the jack (1 or more) with the maximum thrust ratio among the jack groups that do not pull back (propulsion jack group), maximize the pressure, detect the thrust by this jack, and use the detected thrust as a reference The target thrust of the jack is calculated, and the pressure of the jack group is comprehensively controlled so as to maintain the target thrust.

A specific example of the control will be described.
FIG. 15 shows a control system for controlling the jack group. The hydraulic pressure from the hydraulic pump 6 is controlled by the flow rate control valve 8 controlled by the control device 7, and the source pressure is detected by the source pressure detection pressure sensor 9. Is distributed to each jack 4 while being detected. The distributed hydraulic pressure is individually controlled by a pressure control valve (electromagnetic proportional pressure reducing valve) 10 controlled by a control device 7 and pressure is individually detected by a jack pressure detection pressure sensor 11. The The attitude of the shield machine 1 is detected by an attitude detector 12 such as a gyro and is input to an arithmetic device (personal computer) 13. The control device 7 performs a control operation according to the arithmetic device 13. Control is performed in the following procedure by such a control system.

(1) The attitude detector 12 detects the attitude angles of the shield machine 1 in the horizontal direction and the vertical direction, and sends them to the arithmetic unit 13.

(2) The arithmetic unit 13 obtains a deviation from the target direction as shown in FIG. 16, and obtains a jack operation point Q for correcting the deviation. Furthermore, as shown in FIG. 17, the thrust ratio of each jack (each group when each group is divided) is determined from the jack operating point Q (the ratio that determines what percentage of the total thrust is shared by the jack). The result is sent to the control device 7.

(3) The control device 7 searches for a jack (1 or more) having the maximum thrust from the thrust ratio, sets the jack's pressure control valve 10 to the maximum operating pressure of the hydraulic circuit, and sets this jack as a thrust detection target. To do.

(4) While propelling the shield machine 1 at a predetermined speed, the pressure of the jack 4 as a thrust detection target is detected by the pressure sensor 11 and the detected pressure is sent to the arithmetic unit 13 to set the jack as the thrust detection target. Find the current thrust of 4.

(5) The target thrust of the jack other than the thrust detection target is calculated by the calculation device 13 from the current thrust and the thrust ratio obtained in (2), and the calculation result is sent to the control device 7 to calculate the target thrust. The pressure control valve 10 is controlled so as to be maintained (closed loop control is performed so that the target pressure is reached).

  By continuously repeating the above, the shield machine 1 is propelled by automatically controlling the jack pressure so that it always goes in the target direction.

  The thrust ratio in the above is set to a maximum of the jack of the thrust detection target, and the other jacks are set at some% based on this. If it does in this way, in order to perform pressure control, a jack can be arbitrarily grouped and the pressure can be set up freely. As shown in FIG. 17, with reference to the jack with the maximum thrust as the reference, the jack on the opposite side is the minimum thrust, and the straight line toward the jack with the minimum thrust is provided on both sides in the circumferential direction of the jack with the maximum thrust based on the reference. If a smooth thrust gradient is set, jack moment can be generated efficiently.

  In the simultaneous construction as described above, when pulling back a jack for a segment assembly from a group of jacks, a pull-back operation is performed according to the procedure shown in FIGS. FIG. 18 shows a common procedure for each piece, and FIG. 19 shows parallel processing among a plurality of pieces. Also in this case, the thrust sharing of the jack group is set to have a thrust gradient as shown in FIG.

  In step S11 of the flowchart of FIG. 18, before executing the pullback of the jack to be pulled back when assembling the segments, the jack moments by the propulsion jack group that is actually obtaining the thrust are expressed by the above-described formulas (1) and (2). Ask from. The obtained jack moment of the X component and the Y component (jack moment before pulling back) is referred to as “first jack moment M1” for convenience of explanation.

  FIG. 20 shows the thrust sharing at this time point. The numbers “100”, “80”, and “60” added here indicate that the thrust of the maximum thrust propulsion jack is “100%” and “80% ”,“ 60% ”thrust sharing. In the example of this figure, the tenth propulsion jack is “100%”, the fourth is “80%”, and the first is “60%”. At this time, the first jack moment M1 is a slightly upward moment.

  In the next step S12, the jack moment (jack moment assumed after pulling back) by the jack (propulsion jack group) excluding the jack to be pulled back is obtained. The obtained jack moments of the X component and the Y component are referred to as “second jack moment M2” for convenience of explanation.

  FIG. 21 is an assumption diagram in this case, and shows that the jack moment M2 when calculated without changing the thrust sharing of the jack (propulsion jack group) that is not pulled back is a downward moment.

  In the next step S13 in FIG. 18, the thrust balance in which the first jack moment M1 and the second jack moment M2 are the same, that is, a new thrust ratio (new thrust sharing) for jacks (propulsion jack group) that are not pulled back. )

  FIG. 22 shows the calculated new thrust sharing. In the example of this figure, the sixth propulsion jack is “100%”, the fourth is “60%”, and the first is “20%”. As a result, the second jack moment M2 is an upward moment in the same manner as the first jack moment M1.

  In the next step S14, the jack pressure is gradually controlled so as to achieve the thrust balance obtained in step S13, and the jack pressure to be pulled back is gradually reduced. The steps so far (steps S11 to S14) are operations for gradually depressurizing and pulling back the jack, and FIG. 23 shows a schematic diagram of thrust balance control at this time.

  Next, the jack is pulled back in step S15, and the segments are assembled in step S16.

  In step S17 of FIG. 18, before a part of the jack to be pulled back is additionally propelled as the low pressure jack 4c, the first jack moment M1 is expressed by the above formula (1) by the propulsion jack group 4a that is actually obtaining the thrust. Obtained from equation (2).

  In step S18, a second jack moment M2 assumed when a part of the low-pressure jack 4c is added for propulsion is obtained.

  In the next step S19, a thrust balance is obtained at which the first jack moment M1 and the second jack moment M2 are the same.

  In the next step S20, the pressure of the propulsion jack group 4a is gradually increased so as to achieve the thrust balance obtained in step S19 while adding and pressurizing as a low pressure jack 4c to restore a part of the pulled back jack 4b. Promote by lowering. Up to this point (steps S17 to S20) is the low-pressure propulsion operation while synchronizing the pull-back jack and the propulsion jack.

  In the present invention, the jack in the assembly range of the next piece can be decompressed and pulled back simultaneously with the assembly of the segment of the front piece. Therefore, as shown in FIG. Since some of the steps can be performed in parallel, the assembly cycle can be further shortened.

  FIG. 32 shows a time chart of a construction cycle in which the assembling method of the present invention is compared with the conventional assembling method using a normal segment under the conditions shown in Table 1 below such as the excavation speed, the segment width, and the jack stroke.

  As shown in this figure, in the prior art, one cycle of excavation is completed when the third piece starts to be depressurized, whereas in the present invention, one cycle of excavation is completed when the third piece is assembled. Time can be shortened.

  If the jack is pulled back and further propelled as described above, stable excavation is possible while minimizing the attitude change, moment fluctuation, and speed fluctuation of the shield machine 1, so this method is a simultaneous construction method. Applicable widely. In addition, as shown in FIG. 23, by making the target arrival time of the target pressure −P for depressurizing the pullback jack group and the target pressure + P for pressurizing the propulsion jack group the same, the thrust and moment at the time of pressure fluctuation can be reduced. Variation can be minimized.

Therefore, an example in which time adjustment for pressure change between decompression and pressurization is also performed will be described below.
In FIG. 24, assuming that 10 jacks are arranged in the circumferential direction of the shield machine, the first to third jacks are propulsion jacks, and the fourth to sixth jacks are pulled back. The 7th to 10th are jacking jacks. And after defining as follows, the flow of operation | movement is demonstrated sequentially with reference to FIGS.

PG1: Thrust balance at the start of operation PG2: Thrust balance at the completion of operation M1: First moment of the shield machine generated by PG1 (horizontal component M _X , vertical component M _Y )
M2: second moment of shield machine generated by PG2 M: moment of shield machine during pressure change process

(1) Calculation of initial values for pullback (see FIG. 24)
The pressure and extension speed V of each jack are detected at the start of operation, and the thrust balance PG1, the first moment M1 (M _X , M _Y ) of the shield machine generated thereby, and the hydraulic pressure supply source to the jack The discharge amount of the hydraulic pump is calculated.

(2) Setting of target value for pull back (see FIG. 25)
A thrust balance PG2 for generating a second moment M2 equivalent to the first moment M1 by the propulsion jack group excluding the pullback jack group is set.

(3) Change of pressure for pulling back (see FIG. 26)
While adjusting the pressurization amount + ΔP of the propulsion jack group and the depressurization amount -ΔP of the pullback jack group so that the moment M does not change, that is, M = M1, each time is taken over an arbitrarily set target time T. Change jack pressure gradually at the same time.

(4) Retraction completed (see FIG. 27)
When the target value is reached by the pressure adjustment over the target time T, the pressure changing process is completed.

(5) Additional promotion started (see Figure 28)
In starting the additional propulsion in which a part of the pulled-back jacks (referred to as “additional propulsion jack group”) is returned and propelled, the thrust balance PG1 and the first moment M1 (M _X , M _Y ), and the discharge amount of the hydraulic pump that is the hydraulic pressure supply source to the jack is calculated.

(6) Target value setting for additional promotion (see Figure 29)
The thrust of the additional propulsion jack group is arbitrarily set, and the thrust balance PG2 for generating this and the second moment M2 equivalent to the first moment M1 by the propulsion jack group is set.

(7) Pressure change for additional propulsion (see Figure 30)
While adjusting the pressurization amount + ΔP of the additional propulsion jack group and the depressurization amount −ΔP of the propulsion jack group so that the moment M does not change, that is, M = M1, the target time T set arbitrarily is taken. Gradually change the pressure on each jack at the same time.

(8) Additional promotion completed (see Figure 31)
When the target value is reached by the pressure adjustment over the target time T, the pressure changing process is completed.

When the pressure is changed so that the time required for pressure reduction and the time required for pressurization are the same, the following effects are obtained.
(A) Since the pressure is gradually changed over a certain period of time, there is no impact in the hydraulic system, and the pressure and speed do not fluctuate.
(B) Since the moment does not change, the attitude of the shield machine does not change.
(C) By the above, stable face management (maintenance of face earth pressure, etc.) and accurate excavation direction management during simultaneous construction becomes possible.
The excavation speed can be managed with higher accuracy by performing closed loop control using a speedometer as a detector.

FIG. 1: shows the outline | summary of the shield machine used in the Example of this invention, (A) is simplified sectional drawing, (B) is a front view of the operation mode of a jack. It is the same figure as Drawing 1 (B), and (A) and (B) are the states in a different operation process. It is a perspective view which shows the primary assembly process in the assembly method of a present Example. It is a perspective view which similarly shows a secondary assembly process. 5 to 13 sequentially show specific examples of the primary assembly process and the secondary assembly process. In each figure, (A) shows numbers of jacks arranged in the circumferential direction of the shield machine 1 in order in the clockwise direction. (B) shows the expansion and contraction state of the jack together with the segments, and FIG. 5 shows the first stage of the primary assembly process. This is the second stage of the primary assembly process. It is the third stage of the primary assembly process. This is the fourth stage of the primary assembly process. This is the fifth stage of the primary assembly process. This is the final stage of the primary assembly process. This is the first stage of the secondary assembly process. This is the second stage of the secondary assembly process. This is the final stage of the secondary assembly process. It is a front view which shows the relationship between jack division | segmentation and a jack arrangement | sequence when a segment is divided into 6 and the number of jacks is 24. It is a block diagram which shows the control system which controls a jack group. It is explanatory drawing of attitude control of a shield machine. It is explanatory drawing of the thrust sharing method of a jack. It is a flowchart of a control example. It is a flowchart following FIG. The relationship of the thrust sharing before the pullback in the control example is shown, (A) is a perspective view, and (B) is a front view. The relationship of the thrust sharing assumed after pulling back is shown, (A) is a perspective view, and (B) is a front view. The relationship of the thrust balance after pulling back is shown, (A) is a perspective view, (B) is a front view. It is a relation explanatory view of decompression control of a pullback jack group, and pressurization control of a propulsion jack group. It is an Example which changes an pressure gradually so that the pressure reduction required time of the jack to pull back and the pressure required time of a propulsion jack may become the same time, and is a figure explaining the operation | movement start. It is a figure explaining the setting of a target value similarly. It is a figure explaining the change of a pressure similarly. It is a figure explaining operation completion similarly. It is an Example which changes an pressure gradually so that the pressurization required time of an additional propulsion jack and the decompression required time of a propulsion jack may become the same time, It is a figure explaining the operation | movement start. It is a figure explaining the setting of a target value similarly. It is a figure explaining the change of a pressure similarly. It is a figure explaining operation completion similarly. It is a time chart of the construction cycle which compared the assembly method of this invention with the conventional assembly method by a normal segment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield machine 1A Front trunk | drum 1B Rear trunk | drum 2 Cutter 3 Middle folding mechanism 4, 4a, 4b, 4c Jack 5, 5a, 5b Segment 6 Hydraulic pump 7 Control apparatus 8 Flow control valve 9 Pressure sensor 10 for original pressure detection Pressure control valve 11 Pressure sensor 12 for detecting jack pressure Attitude detector 13 Arithmetic unit

Claims (9)

A shield excavation assembly simultaneous construction method comprising a plurality of jacks arranged at equal intervals on the same circumference, and assembling the segments sequentially in parallel with the excavation of the shield excavator by these jacks,
A plurality of trapezoidal segments short side has a forward-facing front facing excavation, in parallel to this while sequentially assembled every other by a jack that corresponds to the segment in the circumferential direction, adjusting the pressure of the jack which does not correspond to the segment While the primary assembly process to dig the shield machine,
A plurality of trapezoidal segments with the long side facing the front of the excavation are reversed, and the shield excavator is stopped between the alternate forward trapezoidal segments by the jack corresponding to the segment. insert in the axial direction, the shield assembly simultaneous construction methods, characterized in that a secondary assembly process for assembling a trapezoidal segment forward direction. In the primary assembly process, the jack corresponding to the forward trapezoidal segment is pulled back after depressurization, and during that time, the other segment of the jack is propelled to the required stroke while taking the reaction force with the existing segment ring and controlling the posture to assemble the segment . simultaneously pull back the jack corresponding to the forward-facing trapezoidal segments assembled next after decompression, during which further promote while attitude control taking a reaction force in a forward direction trapezoidal segments assembled to the existing segment ring and above the other jack 2. The shield excavation assembly simultaneous construction method according to claim 1, wherein the next forward trapezoidal segment is assembled, and at the same time , the jack corresponding to the forward trapezoidal segment to be assembled next is pulled back after decompression. 3. The shield excavation assembly simultaneous construction according to claim 2, wherein the jack that takes the reaction force in the forward trapezoidal segment that is assembled first is set to a lower pressure than that of the propulsion jack that takes the reaction force in the existing segment ring, and is synchronized therewith. Law . Pulling back the jack is the next step,
A jack moment calculating step of calculating a first jack moment M1 by a jack that is currently obtaining a thrust and calculating a second jack moment M2 by a jack excluding the jack to be pulled back before the jack to be pulled back is pulled back. When,
A thrust balance calculating step of calculating a thrust balance in which the first jack moment M1 and the second jack moment M2 are the same for a jack excluding the jack to be pulled back ;
A jack pulling back step of pulling back the jack to be pulled back while controlling the pressure of the jack according to the calculated thrust balance ;
Shield assembly simultaneous construction method according to claim 2 or 3, characterized in that it comprises a.   5. The shield excavation and assembly process according to claim 4, wherein in the jack pulling back step, the pressure is gradually changed so that the time required for decompressing the jack to be pulled back and the time required for pressurizing the other jacks are the same time. Construction method. When adding a jack to be pulled back, pull back the added jack while keeping the jack that takes the reaction force in the forward-facing trapezoid segment assembled earlier at a lower pressure than the propulsion jack that takes the reaction force in the existing segment ring. The shield excavation assembly simultaneous construction method according to claim 4, wherein:   When propelling by adding a jack to be pulled back, the first jack moment M1 is the moment due to the jack that is actually obtaining the thrust before that, and the moment assumed when propelling by partially adding the jack to be pulled is the first. The shield excavation assembly simultaneous construction method according to claim 6, which is calculated as a jack moment M2 of 2.   5. The shield excavation assembly simultaneous construction method according to claim 4, wherein, when a part of the pulled-back jack is returned, the other jack group is decompressed while maintaining the thrust balance while pressurizing the jack. Shield assembly simultaneous construction method according to any one of claims 1 to 8, characterized in that the trapezoidal segments forward direction and the trapezoidal segments and opposite are substantially the same segment.

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