KR20110114851A - Rubber pads that apply with saddle used for the vibration outside wire reinforcement method of construction - Google Patents

Abstract

An object of the present invention is to increase the degradation of the seismic performance of the upper structure of the bridge, overpass by applying an elastic rubber pad to the saddle.

The present invention can prevent the crack of the bridge beam tension portion due to vertical vibration by forming a vertical shock absorbing portion for absorbing the vertical vibration transmitted from the bridge beam to the upper portion of the saddle portion for reducing the vibration of the upper structure.

Description

Rubber pads that apply with saddle used for the vibration outside wire reinforcement method of construction}

The present invention relates to a seismic reinforcement to prevent the problems such as the lack of ductility for cyclic loads such as earthquake loads by using an external steel wire in more detail in the upper structure and to provide the seismic resistance of the upper structure of the pier.

As for the seismic reinforcement of columns, the bridges constructed before 1992 do not consider seismic design, so there are many problems such as lack of strength and lack of lap joints in the pier reinforcing bars or sufficient overlap joint length at the upper part of the foundation. In addition, due to the earthquake, the structure will be non-linear behavior, and the ductility should be secured accordingly. Premature failure of the joint leads to a sudden drop in seismic performance, resulting in the sudden collapse of the structure, and to increase the seismic performance of bridge structures that do not consider such seismic design.

Slab bridges have rarely been applied with external prestress reinforcement methods in Korea, for two reasons. Since the slab bridge is difficult to install the steel wire fixing device at the end of the slab firstly, and secondly, it is a bridge type that is used when there is almost no space in the bridge, it has been difficult to apply the reinforcement method using the external prestress. This effect directly affects the arrangement of the steel wires and the arrangement of the external wires is designed to have a minimum eccentricity.

In reinforcing existing bridges using external prestress reinforcement method, various types of fixing devices are used to transfer tension of external prestress to the structure. Can be distinguished. In addition, in the external prestress reinforcement method, since the load capacity of the fixing device determines the magnitude of the force of the tension force, it is a core technology of the external steel wire reinforcement method. Therefore, the criteria for classifying the external prestress reinforcement method according to the type and the supporting method of the fixing device. This can be In addition, various fixing devices have been developed and studied using the above-mentioned fixing device using a support method or a fixing device type. The fixing devices derived in this way are mainly used for RC and PSC girder bridges, and can be applied to steel bridges or other structures using the respective fixing devices. In recent years, improved fixing devices have been developed that improve the structural rationality, stability, constructability and economic feasibility by approaching not only through existing fixing methods but also based on them.

In the case of external prestress reinforcement, which is adaptable to the structure and offers excellent structural performance, the reinforcing effect depends on the load capacity of the end anchoring device, which determines the layout of the external steel wire and the amount of tension. Therefore, according to the type of end fixing device is classified into a number of construction methods and is being developed. Determining the load capacity of a bridge before the introduction of external prestress to the bridge in use is the most important issue in reinforcement work. It is important to estimate the loss of prestress in this load capacity evaluation, and therefore, research on prestress loss analysis should be conducted.

In the case of reinforcement using external prestress in general PC bridges, studies have been conducted on reinforcement methods using external prestresses for PSC beam bridges and slab bridges. Szailard (1959) published a study on reinforcement using parabolic tension members along the span. This study assumes that the girder and the concrete slab are fully integrated. Abbot (1960) used elastic beam theory to study the effects of linearly placed prestresses, calculate stresses along spans, and to consider buckling problems of upper directional displacements and lower flanges. And displacement are compared with the actual experimental values. Hoadly (1963) studied the behavior of prestressed straight composite beams, suggesting that pre-tensioned steel beams support the fixed load of the structure. Tachibana et al. (1964) studied the behavior of two rigid composite bridges reinforced with bent-up prestresses. Through this study, the composite bridges reinforced with external prestresses showed almost similar load capacity as the post-tensioned rigid composite bridges. Revealed. Regan (1967) proposed a simple strain method "to analyze external prestressed bridges. This study assumes a linear distribution of stresses and excludes the discontinuities of stresses at the joints. It is concluded that the failure of the structure results from the destruction of the concrete slab rather than the failure of the tension member.

Since then, studies on external prestress on bridges have continued. Therefore, the elastic rubber pad is used to absorb the vibration of the bridge by using a rubber pad with a strong elastic force, not a mere saddle, and to reduce the pursuit.

An object of the present invention is to obtain a load-bearing effect of the upper structure while absorbing shock and vibration by using an elastic rubber pad in the leaflet saddle portion of the external wire reinforcement method.

By using a horizontal shock absorbing part in which the middle of the pair of right and left tensile wires of the saddle portion is in close contact with each other, it is possible to prevent cracking of the bridge beam tension due to the horizontal vibration of the tensile steel wire. In addition, the inner surface of the steel wire insertion groove portion and the outer surface of the tensile steel wire are brought into close contact with each other, thereby maximally improving the vibration absorption effect in the horizontal shock absorbing portion.

Fig. 1 Saddle section
2 saddle front view
Figure 3 Saddle Settlement Drawing

1 The degree of mold fixation of the pad in the manufacture of a saddle is closely related to the impact reduction efficiency and is one of the important factors in technical research, so accurate dimension measurement and firm elastic rubber pad attachment are essential. Figure 1 is a diagram illustrating the application of the pad in the above picture.

Fig. 2 shows the elastic rubber pad in the mold member extending between the upper structure in the bridge and the PSC-Beam of the upper structure in the saddle portion.

3, when the elastic pad is installed in the mold, it is required to be settled in the correct position. For this reason, if the molds are not balanced in both molds, the bridging and cracking of the bridge due to the eccentricity are likely to occur. Compared with the elastic pad of the fixing unit, the elastic pad of the saddle requires a wide range of fixing surfaces, so it is expected that the efficiency will be higher in terms of impact reduction, but there will be many difficulties in terms of construction. Therefore, much research should also be carried out in the field of technology development in pad application.

(1) elastic rubber pad
(2) mold

Claims (1)

(Fig. 2) is the part connected to the mold (Fig. 3) and it can surely reduce the shock and vibration of the superstructure when external load is applied.

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