SU1281615A1 - Mobile thrust supporting part of bridge - Google Patents

Abstract

The invention relates to the field of bridge construction and can be used in supporting parts of bridges and other building structures, mainly subject to dynamic and seismic influences. The purpose of the invention is to increase the operational reliability of operation with dynamic and seismic effects and to ensure stable thrust value. The asporna movable support part of the bridge is made with a lower triangular bridge facade with a hollow support plate 6 equipped with a wedge-shaped support 12, the upper support plate 5 is made in the form of an open bottom box and the volume of the lower support plate 6. The roller 7 placed between the upper 5 and bottom 6 base plates, in contact with a horizontal sheet 10 of the box 5. 9 Il. with (L

Description

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The invention relates to bridge engineering and can be used in supporting portions of bridges and other building structures, mainly subject to dynamic and seismic effects.

The purpose of the invention is to increase the operational reliability of operation under dynamic and seismic effects and to ensure a stable value of thrust.

Figure 1 shows the span beam bridge with a spacer movable support part, a general view; Fig. 2 is a longitudinal support longitudinal section; on fig.Z - section aa in figure 2; figure 4 - section B-Bnafig 2 in fig.Z - section bb In figure 2; Fig. 6 shows a box-like upper support plate, view along the facade of the bridge; in fig „view G in fig.6; Fig.8 - hollow lower support plate, view along the facade of the bridge; Fig "9 - type D in Fig.V.

The bridge includes supports or abutments 1 and the superstructure 2 supported on the supports through the fixed support part 3 and the movable support-support part 4.

The movable movable support part includes an upper support plate 5 fixed on the end section of the superstructure 2 and a lower hollow support plate 6 fixed to the support with the upper edge sloping in the direction of the span, a cylindrical roller 7 placed between the upper and lower support plates. The upper support plate 5 is made in the form of an open bottom box, the longitudinal walls 8 of which are made in the middle of the length with coaxial holes 9 under the roller 7, in contact with the horizontal sheet 10 of the box 5, and are located with a gap relative to the longitudinal ribs 11 of the lower support plate 6 with mutual overlap them at least part of the length.

The bottom support plate in the form of a hollow box triangular along the façade of the bridge is provided with a lacquer-like stop 12 fixed on its upper inclined face 13, while the base of the wedge-shaped stop 12 faces toward the span and is located with a gap relative to the rear transverse wall 14 of the box 5 exceeding the horizontal displacement

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U of the roller 7. The front transverse wall of the box 5 with the horizontal sheet retainer 15 is made with slots 16 for the longitudinal ribs 11 of the lower support plate. The transverse wall of the duct 5 with the latch 15 is located along the facade of the bridge with a gap relative to the front, closest to the end of the span, the end of the lower support plate, exceeding the maximum horizontal displacement i of the roller.

The inclined face 13 of the lower support plate 6 is made of a material with varying length hardness and surface roughness, respectively, decreasing and increasing from the initial position of the roller in the middle of the lower plate to its ends. The preferred angle of inclination of the upper face of the bottom plate to the horizontal plane is oi. 5GZS.

The bottom support plate 6 is fixedly mounted on the tip of the support 1 (or the cabinet wall is fixed), for example, by means of anchor bolts 17.

The movable support part of the bridge works as follows.

When exposed to vertical loads on the superstructure, an inclined supporting reaction arises at an angle, decomposing into vertical and horizontal components, the latter being numerically equal to the value of the thrust. With a slight inclination of the upper rpaHji of the lower support plate, the vertical support reaction differs slightly from the inclined age with increasing angle about.

The transfer of thrust in the support part from the support to the superstructure is transmitted through the lower support plate with an inclined upper edge, a cylindrical hinge and the longitudinal walls of the upper box-shaped support plate, providing for any deflection of the span structure of the resulting support reaction and eliminating the possibility of slippage of the roller.

Making the angle uL of inclination of the upper face of the lower support plate is equal to

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5-30 provides the possibility of rational adjustment of the stress state both in the pillars and in the superstructures.

In order to reduce the lifting of the ends of the span with horizontal movements of the span from temperature changes, shrinkage, creep, concrete, the coefficient of friction of the inclined face of the lower base plate has a variable value increasing from the initial position of the roller in the middle of the lower plate to its ends.

High reliability of the operation of the proposed spacer support under the action of dynamic and seismic loads is provided by the presence of special limiters of vertical and horizontal displacements, namely: the longitudinal and transverse walls of the box-shaped upper baseplate, the wedge-shaped support on the inclined face of the lower hollow plate, the horizontal retainer slots under the longitudinal ribs of the bottom plate.

Making an inclined face of the lower hollow slab with variable hardness and variable surface roughness, respectively, decreasing and increasing from the initial position of the roller in the middle of the bottom plate to its ends, contributes to the damping rate of dynamic and seismic vibrations of the bridge, and the selection of the corresponding cross section of the transverse walls is box-shaped the upper plate provides the possibility of breaking one of them in the design seismic shocks.

Feature of work of the basic part

. It is also the fact that when the seismic shocks are relatively weak over time, rolling friction is realized, since the roller can roll on a sloping ground plate. With strong but short-term seismic shocks, the skating rink will take place on an inclined base plate. At the same time, in both cases, the coefficient of friction is variable along the length of the base plate, and during sliding it is achieved due to the variable surface roughness of the base plate along the length, for example, the polished section in the middle part of the length and the unpolished parts on the rest of the length of the lower support plate. Variable ratio

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Rolling friction is achieved by making an inclined support face made of materials with different hardness, for example using surfacing from high-grade steel in the middle part of the lower support plate. In this case, the higher the hardness of the bodies in contact with the roller - the lower support plate, the smaller the coefficient of rolling friction.

Thus, due to the different surface treatment and the use of materials of different hardness in the inclined face of the lower support plate along its length, the coefficient of friction of sliding and rolling is variable along its length, which allows for more effective damping of bridge vibrations under dynamic and seismic effects. x

Claims (1)

Invention Formula The axial movable supporting part of the bridge includes an upper support plate fixed on the end section of the superstructure, a lower support plate mounted on the support with an upper edge inclined in the direction of the span, and a cylindrical roller that is valuable between the support plates and is in contact with them that, in order to increase operational reliability during dynamic and seismic effects and to ensure a stable thrust, the lower support plate is made in the form of a triangular on the facade of the pu bridge a body box with internal longitudinal ribs, the sloping face of which is provided with a wedge-shaped stop, the base facing the side of the span and has a decreasing hardness and increasing roughness f the upper support plate is made in the cross section of the bridge in the form of a duct open to the bottom, in the middle part of the longitudinal walls of which are made coaxial holes for the roller, and the face of the duct on the end of the span is provided with a horizontal sheet an inclined face of the lower support plate and having slots under its longitudinal ribs, with the upper support plate mounted relative to the upper support plate with a retainer and the edge of the lower support plate j and the gap between wedge shaped Noah Alita’s value is the maximum horizontal movement of the roller. / ig.Z 8 § fO 15 / G 6 fz Z f FIG. five vig / J uzJ