JPS6047197A - Method of curve propulsive construction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curve propulsion method, and more particularly to a method for propelling a pipe, such as a hump pipe, along a curve.

Propelling the Huyum pipe along a curved excavation shaft over the entire length of the propulsion line or along a section thereof is required when burying a sewerage system or the like. Several methods have been proposed for this purpose, but none of them were satisfactory. for example,
When a pipe is propelled along a bend using the normal propulsion method, a concentrated load is applied to the pipe at the center of the curvature, which can cause major damage to the pipe. Therefore, between adjacent tubes (vI
1f;
Attempts were made to allow additional power to be added. Shigashi,
In this attempt, it is not easy to select an appropriate force and fill the gap between the tubes, so the thrust cannot be applied evenly.

In addition, multiple hydraulic jacks are placed between adjacent propulsion pipes along the pipe circumference, and these jacks are connected to seven hydraulic machines in parallel, so that when seven jacks extend, the other jacks contract. A method was used to make the whole thing work like a universal joint. However, with this method, no special restraining force is applied, so the tube array tends to shift toward the side where the ground reaction force is smaller, and therefore the tube array cannot be maintained in the desired bent state. Another proposal was to insert intermediate thrusters between adjacent propulsion tubes to increase the number of intermediate thrusters and reduce the transmitted thrust, but this was impractical due to poor propulsion efficiency. As described above, all conventional methods have drawbacks.

This inventor inserted a plurality of hydraulic jacks along the pipe circumference between adjacent propulsion pipes, and when connecting these jacks to a hydraulic machine, the hydraulic jacks were inserted into two jacks, a right half and a left half. The jacks belonging to the same group are connected in parallel and connected to a hydraulic machine, and each jack group is operated by a separate hydraulic machine, and each hydraulic machine adjusts the stroke difference between the jacks. Set it up in advance,
Tried to propel the tube. As a result, by giving a fixed stroke difference between the right half jack and the left half jack, the curvature of the drilled hole varies depending on the location, so it is necessary to adjust the stroke difference to the curvature. Therefore, the load was applied to either the right half or the left half, which resulted in more damage to the tube.

Therefore, in the above-mentioned attempt, the inventor decided not to maintain a fixed stroke difference between the left-half jack group and the right-half jack group, but to advance while adjusting the stroke difference. Moreover, an attempt was made to propel the tube by matching the Km to the thrust shown by each jack group. In other words, although there has been no attempt to propel the vehicle while measuring the thrust by the left and right half jack groups, the inventor has developed a method to measure the thrust by the left and right jack groups separately. We decided to measure this thrust and change the strike force difference based on this thrust. Specifically, each of the above thrust forces is controlled so as not to exceed the allowable thrust resistance of the end face of the propulsion tube, and the difference between the thrust forces applied to the left and right jack groups is controlled so as not to exceed the allowable longitudinal shear force of the propulsion tube. However, within this range, the stroke difference between the right half and left half jack groups was made to be as close to the predetermined curvature as possible. In this way, Jf
It has been found that the rj advancing tube can be propelled along a curved line with less damage to the tube. This invention was made based on such knowledge.

This invention involves inserting a plurality of hydraulic jacks along the rehe/circumferential direction between adjacent propulsion pipes or between several pipes, and replacing the jacks at each stage with the jack group on the right half. The jack groups on the left half are numbered separately, and the left and right jack groups are connected to different hydraulic machines for each stage.In straight sections, the left and right jack groups are stopped at the middle position of the same stroke, and in curved sections, the right jack groups are connected to different hydraulic machines. The strokes of the jack groups on the left and right sides are extended by the outer edge of the curve and contracted by the inner edge to bring the tube arrangement closer to the design curve. At this time, the thrust force exerted by each jack group exceeds the allowable thrust resistance of the end face of the tube. It is characterized by extending or contracting each jack group for propulsion while controlling the difference in thrust between the left and right jack groups so that it does not exceed the 81-force shear force in the longitudinal direction of the tube. This relates to the curve propulsion method.

The method of this invention is explained below based on the drawings. In the accompanying drawings, FIG. 1 is a horizontal sectional view of the propulsion tube when it advances to Jll without bending left and right according to the method of the present invention, and FIG. 2 is a vertical sectional view taken along the line ■-■ in FIG. It is a diagram.

In FIGS. 1 and 2, / to 3 are propulsion tubes, // to /Z and 2/ to 2z are hydraulic jacks. As shown in Fig. 2, the hydraulic jacks // to /2 are divided into jack groups /lz// and /, 2 on the right half, and jack groups /j\/g and /j on the left half. . Each half of the Jyatsuki group, e.g. Jyatsuki group /l 1/
/ and /, 2 are connected in parallel to the same one hydraulic machine. Similarly, other Jatsugi groups /J-/G and /3 are also connected in parallel to another hydraulic machine. The right half and left half are
Divided by a vertical plane passing through the center of the propulsion tube.

In the method of this invention, in the case of straight garlic propulsion, the left and right jack groups are stopped at the same intermediate position of the stroke.

An example of the expansion and contraction of the jack by the hydraulic machine when moving from linear propulsion to curved propulsion according to the method of this invention is as follows. First, all the jacks, both the left half jack and the right half jack, are uniformly extended to approximately the middle position of the maximum stroke. For example, when using a hydraulic jack with a maximum stroke of JOmm, first extend all the jacks to a position where they are extended by 2 jvans, and then stop the hydraulic pulp in this state. Then, according to the principle of hydraulics, the jacks connected in parallel to the seven hydraulic valves work to distribute the thrust evenly, so no uneven pressure is applied between the jacks connected to the same hydraulic machine.

When the propulsion tube reaches the starting point of the curve, for example, when bending to the left, the jack groups /, gS// and /2 on the right half are extended, and the jack groups /, 5\/g and /3 on the left half are shortened. Then, since the jacks belonging to the same group in the right half or the left half are connected in parallel, they each extend and contract while distributing equal thrust. As a result, the jacks on the right half become longer as they are located on the right, and the jacks on the left half become shorter and shorter as they are located on the left. Thus, each jack on the right half and the left half, as shown in FIG.
/ extends the longest, then the jack /2 is the longest, and the leftmost jack /da contracts the most, all the jacks push the propulsion tube / with their tips aligned on a diagonal plane0 This invention method Since the purpose is to advance the propulsion tubes in a bent state, the openings (joints) between adjacent propulsion tubes are
Naturally, this will differ between the right and left sides of the propulsion tube. Therefore, measure the length of the joint on the right and left sides separately. For this measurement, it is preferable to use a limit switch or electronic scale that detects the opening of the joint. Based on the measurements, the joint openings are adjusted so that the curve of the tube array matches the design curve.

To do this, lengthen or shorten the stroke of each jack.

At this time, in the method of this invention, propulsion is performed while adjusting the degree of bending of the propulsion tube while comparing the strength of the propulsion tube with the thrust of the jack so as not to destroy the propulsion tube.

Regarding the strength of the propulsion tube, the permissible thrust resistance and allowable shearing force of the propulsion tube are taken into consideration.

The allowable thrust resistance is the maximum thrust that the propulsion tube can withstand.

The allowable shearing force is the force that can withstand the shearing force that acts on the central cross section of the propulsion tube because the propulsion tube is pushed by the difference in force received from the left and right hydraulic jacks. This kind of strength is
This is known as the inherent strength of the propulsion tube. Although propulsion has never been performed in consideration of the allowable shear force of the propulsion tube, the method of this invention has a major feature in that it performs thrust dl< in consideration of the allowable shear force. There is.

In the method of this invention, the difference in the opening of the joints that occurs when the pipe row progresses according to the design curve is calculated by using the hydraulic jacks in each stage, which are provided separately on the right half and the left half. The purpose of this is to force the tube array to bend and propel it with a curvature as close to the design curve as possible. However, the trajectory of the shaft created by the cutting edge as it excavates the ground is not a neat curve like a compass. Digging is carried out while adjusting the direction from start to finish, so if you look at the tunnel in a big way, it may follow the designed route, but if you look at it in detail, it's a series of zigzag excavations. Since subsequent pipe rows pass through the zigzag tunnel, even if the curvature of the pipe is fixed, the pipe will not work as long as the gap (tail void) created between the excavated shaft and the pipe and the deformation of the ground allow. is not biased, but in reality it may exceed that range.

Therefore, in this case, the curvature of the pipe is not completely fixed, and when a force exceeding the compressive strength and shear strength of the pipe is to be applied, the design curvature is temporarily not fixed. In order to pass through that part, the stroke difference between the left and right jack groups is adjusted. As soon as the stroke passes through that part, the hydraulic machine is activated to return to the original stroke difference.

A specific example of the method of the invention is as follows. Four hydraulic jacks with a thrust of 700 tons and a stroke of 1.50πm were used, and these were attached to the position of H//-7, 2 in Figure 2 to form the right half jack, and/ 'lh/, 51/l; is attached to the left half jack, and the right half jack and left half jack are connected in parallel to separate hydraulic machines for operation. As a propulsion tube, the allowable shearing force is 70
Assume that a tube with a thrust capacity of 300 tons on the right or left half of the tube is used. Also, assume that in the bent state on the design drawing, the difference in joint opening is 20 mm. Before entering this flexed state, the jacks on both sides should be adjusted to 26°.
It is propelled at the position where it reaches a stroke of mm.

In the bent state, the right half jack is further extended by 70πm to make a stroke of jJWTn, while the left half jack is shortened by /'Ovrm to achieve a stroke of 76 mm. Along the way, the thrust shown by the jacks on each half of the left and right sides is measured, and the thrust and the difference between these thrusts are taken out as a display or signal. Extend or shorten the jitters, being careful not to cause any damage.

In the alignment, the right jack// etc. were released too early, and the right jack produced 200 tons of thrust, and the left jack produced 100 thrust.
If it reaches the state of 100 tons, there will be a problem in terms of thrust resistance because the thrust will not reach 100 tons, but if the reaction forces of the jacking of the front and rear pipes are equal, for example, on the left and right, a shearing force of 100 tons will be applied to the tube. Because of this, pressurization of the right half jack and depressurization of the left half jack will be temporarily stopped. As a result of propulsion, for example, if the jack on the left half rises to a thrust of /j0 tons and the jack on the right half drops to a thrust of 7.3θ tons, then the stroke on the right becomes j j rnm
'If /jπn has not been reached on the left side, the jitter on the right half is extended and the jitter on the left half is shortened to bring it to the specified stroke difference.

Also, even if the difference in thrust between the left half and the right half is less than 700 tons, the thrust on the right half is 300 tons and the thrust on the left half is 2.
fO) When one thrust reaches 300 tons, the jack stops extending or contracting. In this way, while keeping the difference between each thrust force and the thrust force below a certain value, the jatsugi is expanded and contracted to create a desired stroke difference.

Even after the pipe is completely bent and there is a stroke difference of 2θt1M between the left and right joints, the jacking at the right end is, in principle, j,! ; πm stroke, leftmost jatsugi is 7
Propulsion is performed while maintaining a stroke of 6 mm, but at this time as well, the difference between each thrust and the thrust is kept below a certain value. For example, if the difference in thrust exceeds 700 tons, even if the stroke difference is insufficient, the extended jack is shortened and the shortened jack is lengthened to reduce the thrust difference. However, if the difference in thrust decreases, the jacking is extended or contracted again to bring the joint opening closer to the desired state.

When the pipe transitions from a bent state to a straight state, the stroke difference is similarly eliminated while suppressing the difference between each thrust to a certain value or less.

The above operation can also be performed fully automatically by inputting data from an electronic scale or pressure transducer into a control circuit such as a computer and using an m-magnetic valve. It is also possible to measure with a folding scale and a pressure gauge and manually move the switching valve of the hydraulic machine. When it is done manually, it is necessary for a large operator to be present at the beginning and end of the bend.

In the middle of the bend, by using two backpressure supplementary reliefs that control the difference in thrust and two reliefs that control the thrust, control can be achieved without any practical problems with just inspection several times a day. be able to. Thus, the method of the present invention can be specifically implemented in a variety of ways.

In the above explanation, the terms "left half" and "right half" were used, but this is only because the explanation was given by taking as an example the case where the propulsion tube is bent left and right to advance. This starting J method can also be used to propel the robot in a bent state in the vertical direction or diagonally vertical direction. In that case, the right half or left half shall be read as the upper half or lower half, diagonally lower right, diagonally lower left, etc., respectively.

According to the method of this invention, the jacks belonging to the same group are divided into the right half jack group and the left half jack group and connected in parallel to the same hydraulic machine, so that the jacks belonging to the same group do not create uneven pressure. , will push the tube with a uniform thrust. On top of that, we decided to operate the right half jack and the left half jack by separate hydraulic machines, so it is possible to extend one jack and shorten the other jack, making it possible to freely change the inclination. I can do it.

Furthermore, although this is not a necessary condition for this invention, during the first set, we decided to uniformly extend the left and right jatugi at the middle position, and then extend one and shorten the other. Easier to change the tilt. When changing the tilt, the thrust from each jack is prevented from exceeding the allowable thrust capacity of the propulsion tube, so the tube is less likely to be pushed and damaged, and the difference between the two thrust forces does not exceed the tube's allowable shearing force. Because of this, when the pipe is tilted, it is less likely to crack due to shearing force. Therefore, the tube can be easily propelled in a bent state with less damage to the tube.

[Brief explanation of the drawing]

FIG. 1 is a horizontal sectional view of a propulsion tube when it is propelled while being bent left and right according to the method of the present invention. FIG. 2 is a vertical sectional view taken along the line l'1-TI in FIG. 1.

Claims (1)

[Claims] Adjacent: I 'f and the left half jack group, and for each stage, the left and right jack groups are grouped separately and connected to different hydraulic machines, and in straight sections, the left and right jack groups are stopped at the middle position of the same stroke. Then, in the curved section, the strokes of the right and left jack groups are extended on the outside of the curve and contracted with the inner ring to bring the tube arrangement closer to the design curve. At that time, the thrust applied to each jack group is Propulsion is carried out by extending or retracting each jack group while controlling the thrust so as not to exceed the allowable thrust resistance of the end face of the stand, and controlling the difference in thrust between the left and right jack groups so that it does not exceed the permissible shearing force in the vertical direction of the stand. A curved propulsion method characterized by: