JPS6016533B2 - Steel plate cell fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a joint for attaching an arc portion to connect steel plate cells of a steel plate cell structure for port construction such as a placing cell or a vibro-driving cell.

Conventionally, cell structures for port construction were assembled from flat sheet piles using temporary frames on site, but with the advent of the synchronous pipe hammer, huge single cells made of welded steel plates suddenly attracted attention. became. However, if the arc part was also made of a single steel plate, there would be a huge problem in construction.In the past, this problem was solved by specially fabricating deformed steel sheet piles to fit on-site, but all arc joints were made with a special structure, which caused construction errors. must be allowed as a customer. However, such an arc joint structure is difficult to put into practical use.

An object of the present invention is to provide a steel plate cell arc joint that has sufficient strength required in the design of a steel plate cell and is easy to construct.

The joint of the present invention has high reliability in its strength, allows complex external forces to be widely distributed over the steel plate, and does not cause excessive stress locally. Embodiments of the present invention will be described below with reference to the drawings.

The configuration of the joint A of the present invention is as follows. That is, as shown in the explanatory plan view of the grip hardware in FIG. 1, a joint A is used as a joint between the steel plate cell 1, which is the main embankment body, and the arc portion steel plate 2. The interior of the embankment body is filled with sand, similar to the conventional cell embankment body made of flat steel sheet piles assembled on-site. Details of the joint A will be explained with reference to a cross-sectional plan view of the joint in FIG. 2 and a perspective view for explaining the joint in FIG. 6. That is, the joint A of the present invention is constructed by welding the entire surface of the thick-walled steel grout pipe 3 to the end of the arc portion steel plate 2 to create a male metal fitting, which is then slid into the female metal fitting from above.

The female hardware is formed by welding two mutually opposing case plates 4 and a plate-shaped stiffener 6 provided in multiple stages to the outer surface of the main steel plate cell 1. Especially in the case of a large joint, Similarly, a backing steel plate 6 is added to the inner surface of the steel plate cell 1 by plug welding to reinforce it from the inside as well.

As shown in FIG. 6, the lower end of the female hardware is protected by a pointed fin 24 to minimize the increase in penetration resistance caused by the stiffener 6 during steel plate cell casting.

The rubber tube 8 is glued to the steel semicircular cross-section holder 7 that is integrally connected to the case plate 4, and during the grouting work in the later stage of construction, the inside of the tube is pressurized to connect the arc steel plate 2 and the case plate. Completely seal the space between 4. However, depending on the site conditions, sometimes the steel plate 2 may be damaged due to vibration when pouring with a pipe hammer.
There is dust that may damage the rubber tube 8 that is in close contact with the tube.In such a case, it is safe to reduce the pressure inside the tube 8 and shrink the tube. The concept is illustrated in the detailed partial cross-sectional view of the rubber tube in FIG. The pressure is reduced by connecting a vacuum pump 27 to the rubber tube 8 as shown in FIG. Next, a construction method for the joint of the present invention will be explained.

First, the eyepiece 14 is attached to the arc section steel plate 2, as shown in the plan view shown in FIG. 4 showing the tie rod attachment accompanying the arc section hanging work and the perspective view shown in FIG. 5 showing the arc section hanging work.
A turnbuckle 1 attached to a tie rod 13 welded to the eyepiece 14 and connected to the eyepiece 14 via a shirtcle 16.
Adjust the arc part curvature by rotating 5.
Immediately after the steel plate cell main embankment is installed or poured, filler sand is poured into it to make it immovable as an embankment.

At that point, the positions of the joints between the 72 cells and the distances between the cells are precisely measured, and the arc section curvature is adjusted in advance as described above.Next, the arc section steel plate 2 is As shown in Fig. 5, the hoisting support 12 is
The pipe tips 17 of the grout pipes 3 at both ends of the grout pipes are guided to enter the case plates 4 of both steel plate cells, and the first tie rod 13a is lowered to near the sea surface by a slight suspension. For example, loosen the corresponding turnbuckle 15a, remove the pin of the shirtcle 16 from the eyepiece 14, and collect the first tie rod and its accessories.

Furthermore, the second tie rod 13b is also recovered on the sea surface. By the time the third tie rod 13c is removed, the lower end of the arc steel plate reaches the seabed surface, and after penetrating into the ground a little due to its own weight, the descent stops. Next, the lifting support 12 is removed, and a new hydraulic chuck of the synchronous pipro hammer is clamped to the top of the steel plate of the arc part by the action of a hydraulic actuator.
Drive the arc steel plate to the planned depth.

After filling the back of the arc with sand, grout is injected into the joint case.

As shown in the partially cutaway sectional view for explaining grouting construction in FIG. 7, a mortar mixer 25 and a grout pump 26 are both installed on a work barge.

A flexible hose 31 extending from the outlet of the grout pump is attached to the top mounting screw 18 of the grout pipe 3 via the coupler 30. Prior to grout injection, the water pressure in the rubber tube 8 is increased using a pressurized water supply pump 39. Alternatively, it is also good to apply hydrostatic pressure due to a difference in water head. A large number of grout discharge holes 10 are closed below the grout vip 3, and these discharge holes 10 are connected to the case plate 4 in the same manner as in the underwater construction of tremie concrete.
Discharge grout inside. Prior to grout injection, if necessary, sufficient water is supplied through the grout pipe 3 to wash the inside of the case.

A sand puddle 29 is naturally formed in the seabed ground near the tip 24 due to washing, and becomes the base of the grout column. The grouting material used is ordinary cement mortar with some admixture added. As described above, the joint A of the present invention is
The purpose is completely different from that of continuous steel pipe sheet pile joints.
Rather, it corresponds to a "T-type sheet pile" which is a specially shaped connecting metal fitting used to attach the arc part of a flat steel sheet pile cell, and its structural strength is an ultimate tensile strength of 40.
However, it easily clears the design allowable tension of 15 m, and it is actually possible to design it with several times the strength.

Therefore, it becomes possible to plan a large cell for deep water, which has never been possible before. In addition, since the engaging portion of the conventional "T-type sheet pile" uses the grip of a normal flat sheet pile as is, it is inconvenient to use it for a steel plate 0 cell using a synchronous pipe hammer. In other words, when suspending one large arc, the joint requires a considerable dimensional allowance for the male and female engagement, and the grip of conventional steel sheet piles is
Unable to use due to unreasonable mutual spacing and mounting angle. However, according to the joint A of the present invention, these difficulties can be overcome. Figures 3a to 3d are Binshiki diagrams showing the acid rupture pattern, and Figure 3a shows the normal case.

The arrow in the figure indicates the direction in which the load is applied. FIG. 3b shows a case where the male hardware comes off due to deformation of the case plate 4, and is the most likely fracture pattern. Figure 3c shows a case of failure that occurs when welding under the chest of the case plate is insufficient. Although the case shown in Fig. 3d is relatively rare, reinforcement Z is necessary for a large grip. Furthermore, in addition to the three examples shown in the figures, complex external forces act, such as a bending moment due to a horizontal force from the side and a shearing force.

The most effective countermeasure against these fracture patterns is to add a stiffener 6, which replaces the hardening of the injected grout and can three-dimensionally stiffen the entire joint. The curved end of the case plate 4 can be easily processed at a factory specializing in rolls, and there is no problem even if the steel plate is somewhat thick.

The fracture shown in Figure 3b actually occurs when the area around the fillet weld on the leg of the case plate bends, and the entire case gradually deforms like a candle opening, and the fillet weld itself also experiences bending moment due to lateral horizontal force. When the sea bream cutting force is added to the tensile force and acts in a complicated manner, it may be unexpectedly weak, and when assembling it as a case, it must be kept in mind that at least one side of the inner fillet welding cannot be done as it is inside the sheath. . The failures shown in Figures 3b and 3c often occur at the same time. Stiffener 6
The following advantages arise by welding and mounting.

1. The reinforcement of the stiffener prevents deformation of the flame-shaped end curved surface and prevents the male metal fitting from coming off.

For this purpose, the stiffener shape should be designed so as to largely enclose the outside of the case slit, and this portion is used to attach the rubber tube holder 17. 2 By installing the stiffener, the length of the fillet weld between the joint and the cell embankment body increases, and the reliability as a tension joint improves, as shown in Figure 3c.
The weld peeling below the chest of the case plate, as shown in Figure 2, will no longer occur.

3. Three-dimensional stiffening of the stiffener allows stress to be distributed over a wide range.

Steel plate cells are particularly desirable because they use thin steel plates relative to their diameter. Furthermore, not only a simple tensile force but also a bending moment due to a lateral horizontal force and an effort force act on this joint in a complex manner, so the three-dimensional stiffening effect is large. 4. You can freely adjust the stiffener installation interval, making it possible to achieve economic efficiency.

For example, since the soil pressure and water pressure acting on the joint are generally greater in the downward direction, it is preferable that the interval be narrow in the downward direction and wide in the upward direction, as shown in FIG. FIG. 8 is an explanatory diagram illustrating the strain on the steel plate at the arc portion, and shows the results of actual measurement of strain on the arc portion according to an experimental construction example.

In this experiment, six oblique meters were installed vertically at the center of the arc, and data was analyzed and graphed from the dominant oblique angle at each point. In Fig. 8, the solid line 33 indicates the correct position of the perpendicular line 36, and the dotted line 38 indicates the vertical cross-sectional displacement of the steel plate at the center of the arc immediately after the arc is cast, so please note that this is a curved line. I want to be The maximum horizontal displacement difference between the upper and lower ends of the curve is approximately 50/skin. When filling sand is applied inside the arc part, the head inclination meter moves, and as a result, it changes to a shape close to a straight line as shown by the dotted chain line 37 and ends.

During this time, the grout pipe 3 occupies various positions within the case and moves vertically and horizontally. The position where the male hardware is pushed in the most is shown as 34, and the overhanging position is shown as 35. The allowable amount of movement inside the case is generally about 100 m/w in the vertical direction and 50 m/w in the horizontal direction, and since joints with sufficient strength are used, the amount of displacement is naturally regulated, and large distortions will occur. There's nothing wrong.

However, at the flame part, which is the contact point between the male and female hardware, the hardware does not come in smooth contact over the entire upper and lower areas.
Grout is injected to permanently disperse stress and complete the joint structure. The guard steel plate 5 is used only when making a strong tension joint with a large arc radius.

If this is attached to the inside of the steel plate cell 1 by plug welding 9, the cell center deformation shown in FIG. 3d will not occur, and
There is no threat to the welded part under the stiffener leg. In addition, 11 is a filling grout, 19 is a steel plate reinforcing the lower end of the arc, and 2
0 is the top reinforcing steel plate for hydraulic chuck, 21 is the grout pipe installation fillet weld, 22 is the weld under the case plate leg, 23
is the stiffener leg weld, 28 is the protective wire mesh,
32 is a rubber tube connection hose.

[Brief explanation of drawings]

Fig. 1 is an explanatory plan view of the joint of the present invention, Fig. 2 is a cross-sectional plan view of the joint, Figs. FIG. 5 is a perspective view showing the arc part hanging work; FIG. 6 is an explanatory perspective view of the joint;
FIG. 7 is a partially cutaway sectional view for explaining grout construction, FIG. 8 is an explanatory view for explaining distortion of the steel plate at the arc portion, and FIG. 9 is a detailed sectional view for a portion of the rubber tube. A... Arc joint, 1... Steel plate cell, 2... Arc part steel plate, 3... Grout pipe, 4... Case plate, 5... Hair rest steel plate, 6... Stiffener, 7...・Holder, 8... rubber tube, 10... grout discharge hole,
24...Stone milk calendar, 29...Sand puddle. ★18 size 28 ★3 figure o na 3 times b age 3 times C na 3 times d na 4 figure na 8 figure o 9 figure age 5 figure o 6 figure na 7 figure

Claims (1)

[Claims] 1. An arc section steel plate for connecting steel plate cells cast apart from each other, and a vertical section fixed to both vertical end faces of this arc section steel plate and having a kraut outlet at its lower part to form a male metal object. A pipe, a sheath-like case plate forming a female metal fitting whose lower leg is fixed to the vertical side surface of the steel plate cell so as to surround the outer periphery of the pipe through a gap, and an arc-shaped case plate formed at the free end of the case plate. A holder, a sealing tube inserted between the inner surface of the arc-shaped holder and both sides of the arc portion steel plate, arranged in multiple stages spaced apart in the vertical direction and fixed horizontally to the case plate, the arc-shaped holder, and the steel plate cell. A steel plate cell joint characterized by comprising a plate stiffener.