DE1658596A1 - Inclined cable bridge - Google Patents

Description

Dr.-Ing. Ellmut Homberg. I6585 ^c ß Consulting engineer for bridge construction Description of the invention

Additional patent application to the applications file number H 48616 V / 19d and H 58136 V / 19d cable-stayed bridge

To the state of the art

The invention relates to the bridge structure, which in the Patent application, file number H 48616 V / 19d, "cable-stayed bridge" has been described (German Auslegeschrift No. 1235973) and of which it is stated in claim 1 of this application that the stay cables on the pylon and a «stiffening girders are at such small mutual distances be connected that they over the stiffening beam support large areas of its length almost continuously and that the distance between the pylon and the first rope anchor point significantly exceeds the distance between the ropes *

In the additional patent application, file number II 58136 V / 19d, further design variants of the aforementioned bridge system are described, namely a parallel rope guide instead of the tufted one and instead of the rope anchoring lying only in the vertical bridge center plane, "double bracing by 2 support levels laterally outside the Roadway·

Although the characterizing parts of the patent claim · both the aforementioned registrations are completely free of information about certain building materials to be used and thus have general validity, so are the details of the Description and the accompanying sketches specially tailored to steel bridges.

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The cable-stayed bridges built so far, offered in bridge competitions and published in the literature, with any system of cable anchoring, also showed as a building material in the vast majority of cases steel structures, in some special cases also made of steel girders and concrete decks on composite composite structures.

This means that so far the nornal forces in stiffening girders and in the pylon have been wholly or largely through steel Structural members were included, because even with the composite structures, the by far largest proportions of the Normal forces from permanent loads, and these are the decisive factors in large-scale bridge construction, on the steel structure around.

To the invention

The invention described in this supplementary patent application is based on the idea that the structural members, stiffening girders, which are essentially stressed with normal compressive forces and PyIons of the cable-stayed bridge, according to the patent application, file number Π 48616 V / 19d, not made of steel, but of your cheaper building material concrete. Even if the Use of the building material concrete was covered by the previous patent application without explicit mention, then a number of technical features result from the same, the entirety of which in turn represents an invention of a special character.

The use of concrete as a building material for cable-stayed bridges only became practicable through the connection of bit with the support system of the patent application, file number H 48616 V / 19d. Because if for steel bridges in the last Years ago it was recognized that with increasing span, the concentrated guy wires become almost insurmountable lead to constructive difficulties, this applies to a greater extent to the introduction of rope forces into a pure Concrete structure. First the close-meshed rope tensioning system described in the previous patent application

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allows the individual rope forces to be reduced to values of about 1000 Mp and below, which is still constructive with justifiable Allow effort to be anchored in pure concrete structures.

According to the constructive and economic conditions Either the stiffening girder or the pylons or both of the mentioned structural elements can be made of concrete will.

As in the case of a stiffening beam made of concrete, the bending moments must be kept as small as possible because of the tensile bending stresses, it is advisable to choose a tighter rope tension than with a corresponding steel bridge and the ropes brought to the middle of the bridge from the right and left are practical to end close to each other without the interposition of a scil-free section. The structure of one of the invention The corresponding cable-stayed bridge is shown in FIG. 1.

The stiffening beam 1 becomes the pylon 3 by inclined cables 2 exhausted. The guide of the ropes 2 can either be tufted, as shown on the left half of FIG. 1, or parallel to each other, as on the right half of FIG. 1 can be selected.

The cross-sectional structure is also the same as that of a steel bridge possible with rope tensioning in a middle vertical plane in the sense of a central girder bridge as well as with 2 bearing planes outside the roadway.

The stiffening structure 1 of the cable-stayed bridge always has To fulfill 4 constructive and static functions. It is

load-bearing ceiling of the extended roadway in the plan area,.

load-bearing member in the transverse direction of the bridge for transmission and forwarding of those arriving from the road surface Loads on the vertical, rope-braced load-bearing planes,

load-bearing component in the longitudinal direction of the bridge for the distribution of concentrated individual loads over a larger number of Ropes,

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Pressure bar of the Fachwork-like structure, formed made of stiffening beams, pylon and ropes.

All 4 functions are made in a simpler and more functional way Wise perceived through a massive concrete slab.

In the case of bridges with a larger span, it is necessary to take off For reasons of weight saving, the aforementioned individual functions can also be assigned and thus assigned to individual components To pass over an articulated stiffening structure. Such an articulated structure is shown in Fig. 2 in cross section and in Fig. 3 in longitudinal section. the The function of the roadway slab is fulfilled by a concrete slab 4 that is as thin as possible. This is borne by Cross ribs 5, their side consoles 6 in the ropes hang. The load advantage in the longitudinal direction is carried out by one or more main girders 7, while the Normal pressure forces from both the deck 4 as also the main girders 7 are included.

The ropes are firmly anchored in the pylon, two of which are fundamental Construction forms are possible:

In the case of the former, see FIG. 4, the ropes 2 run through the pylon 3. They are inside the pylon from the rising diverted to the falling direction, whereby the vertical reveal forces via corresponding steel * saddles 8 are placed on the concrete. Furthermore, in the Inside the pylon a rope clamp 9 is clamped onto each individual rope 2. This carries one into the concrete of the Dowels reaching into the pylons and thus prevents the rope 2 from sliding lengthways in the steel saddle 8. ·

In the second form, shown in longitudinal section in Fig. 5 and in plan in Fig., The rope 2 coming from the stiffening beam ends with a rope head inside the pylon 3. This rope head is gripped by a steel structure 11 and with the opposite rope head 10 firmly connected. The steel construction 11 sqo-gt

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for a compensation of the horizontal components on the right and on the left of the pylon attacking ropes and only places the vertical components of the rope forces on the concrete and the differential forces from the horizontal components.

The advantage of the invention lies in a more expedient embodiment of the patent application, file number H 48616 V / T9d, described cable-stayed bridge system, wherever there are essentially normal pressure forces act that is suitable and cheap for the reception of these Construction material concrete is used. In contrast to the already known composite structures, an elaborate dimensioning, which is based on the high demands of the Concrete from shrinking and creeping as well as to the high Stress on the steel after shrinkage and creep must be taken into account, avoided.

Because of their greater weight, cable-stayed bridges with concrete reinforcement girders are much stronger Ropes as steel cable-stayed bridges. This fact has further advantages in the wake:

The traffic loads generate because of their small share lower rope elongations in relation to the total load than with steel bridges. This results in significantly smaller bending components in stiffening beams, which is particularly important on the low load-bearing capacity of the concrete on bending tension of Meaning is. Ib association with the normal pressure force that derives from the horizontal component of the rope forces, a slight longitudinal pre-tensioning of the reinforcement beam is generally sufficient to avoid tensile stresses in concrete

The large proportion of dead weight in the stress on the stay cables means that the amplitude of the cable tension is only small under traffic loads. Ia contrast to the In the case of steel bridges, this makes it possible for the ropes to bend in the pylon without affecting the permissible Rope tension removed with regard to the fatigue strength

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would have to be reduced. . '

Hagon, 7.2.1967 J ₄ / L t ^ Wv / v ')

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Claims (8)

Dr.-ing. Hellmut Homberg 1'R ^ A R QC Consulting Engineer for Bridge Construction Patent Claims Additional patent application to the applications file number Il 48616 V / 19d and 1! 58136 V / 19d cable-stayed bridge 1. Cable-stayed bridge with stay cables arranged one above the other, which are attached to the reinforcement girders outside the main girder webs and at the pylon over a larger area of the pylon height are connected distributed, according to the descriptions of the German Auslegeschrift No. 123S973 characterized by that the stiffening beam or the pylons or both structural members are created from the building material concrete. 2. Cable-stayed bridge according to claim 1, characterized in that the inclined cables are arranged in tufts. 3. Cable-stayed bridge according to claim 1, characterized in that that the stay cables are arranged parallel to each other. 4. Cable-stayed bridge according to claim 1 and 2 or 3, characterized characterized in that the guy ropes are arranged in 2 vertical support levels laterally outside the roadway will. 5 »Cable-stayed bridge according to claim 1 and 2 or 3, characterized characterized that the ropes from the right and left without the interposition of a rope-free section until tight be brought up to the middle of the bridge. 6. Cable-stayed bridge according to claim 1 and 2 or 3, characterized in that the cables are ia pylon rising from initially falling branch traversed back and shear-resistant manner by means of a aufgeklenuaten dowelling nit the pylon connected. 009800/0987 7. Cable-stayed bridge according to claim 1 and 2 or 3, characterized characterized in that the rope heads opposite one another inside the concrete pylon are secured by an intermediate shell A pure steel structure can be connected to one another in such a way that this steel structure is only the vertical components of the rope forces and the difference values of the horizontal components of the opposite ropes are deposited on the concrete. 8. Cable-stayed bridge according to claim 1 and 2 or 3, characterized in that the roadway panel lying between the main girders is designed as a transversely tensioned rib plate. Hagen, February 7th, 1967 009808/0 98 7 _eA O ORIGINAL Lee on the back