Sliding pendulum bearing and method of dimensioning such a bearing

Abstract

A sliding pendulum bearing is used to protect a construction against dynamic stresses from predominantly horizontal earthquake excitation with a first sliding plate, a second sliding plate and a slider movably arranged between both sliding plates, wherein each of the two sliding plates has a curved main sliding surface and the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate, wherein the first main sliding surface is designed for a first load case and the second main sliding surface is designed for a second load case which differs from the first load case.

Claims

1. A sliding pendulum bearing for protecting a construction against dynamic stresses from predominantly horizontal earthquake excitation, having a first sliding plate, a second sliding plate and a slider movably arranged between both sliding plates, wherein each of the two sliding plates has a curved main sliding surface and the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate, wherein the first main sliding surface is designed for a first load case and the second main sliding surface is designed for a second load case which differs from the first load case, wherein the first and the second load cases represent specific peak ground acceleration values of corresponding earthquakes, and wherein the first main sliding surface has a first effective radius of curvature R.sub.eff,1 and the second main sliding surface has a second effective radius of curvature R.sub.eff,2, wherein the sum of R.sub.eff,1 and R.sub.eff,2 is at least 1.4 times the effective radius of curvature of a sliding pendulum bearing having only one curved main sliding surface.

2. The sliding pendulum bearing according to claim 1, wherein the first main sliding surface is designed for a first load case with a value for a peak ground acceleration (PGA value) which corresponds at most to the PGA value of the maximum credible earthquake and at least to the PGA value of the design basis earthquake.

3. The sliding pendulum bearing according to claim 1, wherein R.sub.eff,1 and R.sub.eff,2 are each at least 0.7 times the effective radius of curvature of a sliding pendulum bearing having only one curved main sliding surface.

4. The sliding pendulum bearing according to claim 3, wherein the second effective radius of curvature R.sub.eff,2 is in the range from 0.90 to 1.5 times the first effective radius of curvature R.sub.eff,1 and is particularly preferably equal to the first effective radius of curvature R.sub.eff,1.

5. The sliding pendulum bearing according to claim 1, wherein the first effective radius of curvature R.sub.eff,1 approximately as large as for a sliding pendulum bearing with only one curved main sliding surface, and the second effective radius of curvature R.sub.eff,2, in the range from 0.75 to 2 times the first effective radius of curvature R.sub.eff,1.

6. The sliding pendulum bearing according to claim 5, wherein the second effective radius of curvature R.sub.eff,2 is equal to the first effective radius of curvature R.sub.eff,1.

7. The sliding pendulum bearing according to claim 1, wherein the first effective radius of curvature R.sub.eff,1 in metres corresponds approximately to 0.25 times the square of a desired isolation cycle duration T.sub.ISO in seconds of the construction to be protected with the sliding pendulum bearing.

8. The sliding pendulum bearing according to claim 1, wherein the first main sliding surface has a first coefficient of friction .sub.1 for the friction with the slider which is approximately as large as for a sliding pendulum bearing having only one curved main sliding surface, and the second main sliding surface has a second coefficient of friction .sub.2 which is lower than .sub.1 and which is in the range from about 0.2% to 1.7% when the second main sliding surface is lubricated and in the range from about 2% to 3.5% when the second main sliding surface is not lubricated.

9. The sliding pendulum bearing according to claim 1, wherein the second main sliding surface has a limitation means for limiting the displacement capacity of the slider on the second main sliding surface, wherein the limitation means is designed as an annular abutment and the limitation means does not limit the total displacement capacity of the bearing.

10. The sliding pendulum bearing according to claim 9, wherein the limitation means is formed such that the displacement capacity D.sub.2 of the slider on the second main sliding surface is substantially less than or equal to the displacement capacity D.sub.1 of the slider on the first main sliding surface.

11. The sliding pendulum bearing according to claim 1, wherein the slider has two slider parts which are in surface contact with one another via a curved subsidiary sliding surface, wherein the first slider part is in contact with the first main sliding surface and the second slider part is in contact with the second main sliding surface.

12. The sliding pendulum bearing according to claim 11, wherein the sliding pendulum bearing has different sliding paths, different coefficients of friction and different effective radii on the two main sliding surfaces.

13. A method for dimensioning a sliding pendulum bearing for protecting a construction against dynamic stresses from predominantly horizontal earthquake excitation, having at least a first sliding plate, a second sliding plate and a slider movably arranged between both sliding plates, wherein each of the two sliding plates has a curved main sliding surface and the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate, wherein the first main sliding surface is designed for a first load case and the second main sliding surface is designed for a second load case which differs from the first load case, wherein the first and the second load cases represent specific peak ground acceleration values of corresponding earthquakes, and wherein the first main sliding surface has a first effective radius of curvature R.sub.eff,1 and the second main sliding surface has a second effective radius of curvature R.sub.eff,2, wherein the sum of R.sub.eff,1 and R.sub.eff,2 is at least 1.4 times the effective radius of curvature of a sliding pendulum bearing having only one curved main sliding surface.

14. The method for dimensioning according to claim 13, wherein the slider has two slider parts which are in surface contact with one another via a curved subsidiary sliding surface, wherein the first slider part is in contact with the first main sliding surface and the second slider part is in contact with the second main sliding surface.

15. The method for dimensioning according to claim 13, wherein the first main sliding surface is designed for a first load case with a value for a peak ground acceleration (PGA value) which corresponds at most to the PGA value of the maximum credible earthquake and at least to the PGA value of the design basis earthquake.

16. The method for dimensioning according to claim 13, wherein in a first step, a first effective radius of curvature R.sub.eff,1 and a first friction value .sub.1 are determined for the first main sliding surface under the assumption that the sliding pendulum bearing has only one single main sliding surface, wherein the second effective radius of curvature R.sub.eff,2 is selected in the range from 0.75 to 2 times the radius of curvature of the first main sliding surface, and a second coefficient of friction .sub.2 is selected for the second main sliding surface, wherein the second coefficient of friction .sub.2 is selected between 0.2% and 2.0% of the first effective coefficient of friction .sub.1, in order to ensure a predefined minimum shear resistance.

17. The method for dimensioning according to claim 16, wherein the second effective radius of curvature R.sub.eff,2 is selected in the range from 0.75 to 1.5 times the radius of curvature of the first main sliding surface.

18. The method for dimensioning according to claim 16, wherein the second coefficient of friction .sub.2 is selected between 0.4% and 1.5% of the first effective coefficient of friction .sub.1.

19. The method for dimensioning according to claim 18, wherein the second coefficient of friction .sub.2 is selected between 0.6% and 1.25%, or which is less than or equal to the first effective coefficient of friction .sub.1.

20. A sliding pendulum bearing for protecting a construction against dynamic stresses from predominantly horizontal earthquake excitation, having a first sliding plate, a second sliding plate and a slider movably arranged between both sliding plates, wherein each of the two sliding plates has a curved main sliding surface and the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate, wherein the first main sliding surface is designed for a first load case and the second main sliding surface is designed for a second load case which differs from the first load case, wherein the first and the second load cases represent specific peak ground acceleration values of corresponding earthquakes, wherein a first effective radius of curvature R.sub.eff,1 of the first main sliding surface in metres corresponds approximately to 0.25 times the square of a desired isolation cycle duration T.sub.ISO in seconds of the construction to be protected with sliding pendulum bearing.

21. A sliding pendulum bearing for protecting a construction against dynamic stresses from predominantly horizontal earthquake excitation, having a first sliding plate, a second sliding plate and a slider movably arranged between both sliding plates, wherein each of the two sliding plates has a curved main sliding surface and the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate, wherein the first main sliding surface is designed for a first load case and the second main sliding surface is designed for a second load case which differs from the first load case, wherein the first and the second load cases represent specific peak ground acceleration values of corresponding earthquakes, wherein the first main sliding surface has a first coefficient of friction .sub.1 for the friction with the slider which is approximately as large as for a sliding pendulum bearing having only one curved main sliding surface, and the second main sliding surface has a second coefficient of friction .sub.2 which is lower than .sub.1 and which is in the range from about 0.2% to 1.7% when the second main sliding surface is lubricated and in the range from about 2% to 3.5% when the second main sliding surface is not lubricated.

22. A sliding pendulum bearing for protecting a construction against dynamic stresses from predominantly horizontal earthquake excitation, having a first sliding plate, a second sliding plate and a slider movably arranged between both sliding plates, wherein each of the two sliding plates has a curved main sliding surface and the slider is in surface contact with a first main sliding surface of the first sliding plate and with a second main sliding surface of the second sliding plate, wherein the first main sliding surface is designed for a first load case and the second main sliding surface is designed for a second load case which differs from the first load case, wherein the first and the second load cases represent specific peak ground acceleration values of corresponding earthquakes, wherein the second main sliding surface has a limitation means for limiting the displacement capacity of the slider on the second main sliding surface, wherein the limitation means is designed in particular as an annular abutment and the limitation means does not limit the total displacement capacity of the bearing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, advantageous embodiments of the present invention are described using figures. Therein,

(2) FIG. 1A shows schematically a first prior art design of a sliding pendulum bearing;

(3) FIG. 1B shows schematically a second prior art design of a sliding pendulum bearing;

(4) FIG. 1C shows schematically a third prior art design of a sliding pendulum bearing;

(5) FIG. 1D shows schematically a first prior art design of a sliding pendulum bearing;

(6) FIG. 1E shows schematically a diagram in which the course of the maximum absolute acceleration occurring in the construction is shown as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing designed according to the prior art;

(7) FIG. 2 shows schematically the design of a sliding pendulum bearing corresponding to a first advantageous embodiment of the sliding pendulum bearing according to the invention;

(8) FIG. 3 shows schematically the design of a sliding pendulum bearing corresponding to a second advantageous embodiment of the sliding pendulum bearing according to the invention;

(9) FIG. 4A shows schematically a diagram in which the course of the maximum absolute acceleration occurring in the construction is shown as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing designed according to a first embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum) in comparison to already known comparable bearings (cf. curves for Friction Pendulum and Pendulum with optimized viscous damping);

(10) FIG. 4B shows schematically a diagram in which the course of the maximum horizontal bearing force (maximum of bearing force) as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing designed according to the first embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum) in comparison to already known comparable bearings (cf. curves for Friction Pendulum and Pendulum with optimized viscous damping);

(11) FIG. 4C shows schematically a diagram in which the course of the maximum total bearing displacement as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing designed according to the first embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum) in comparison to already known comparable bearings (cf. curves for Friction Pendulum and Pendulum with optimized viscous damping);

(12) FIG. 4D shows schematically a diagram in which the course of the residual total bearing displacement as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing dimensioned in accordance with the first embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum) in comparison with already known comparable bearings (cf. curves for Friction Pendulum and Pendulum with optimized viscous damping);

(13) FIG. 5A shows schematically a diagram in which the course of the maximum absolute acceleration occurring in the construction (maximum of absolute acceleration) as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing designed according to a second embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum) in comparison to an already known comparable bearing (cf. curve for Friction Pendulum);

(14) FIG. 5B shows schematically a diagram in which the course of the maximum horizontal bearing force (maximum of bearing force) as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing designed according to the second embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum in comparison to an already known comparable bearing (cf. curve for Friction Pendulum);

(15) FIG. 5C shows schematically a diagram in which the course of the maximum occurring bearing displacement (maximum of total bearing displacement) as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing dimensioned according to the second embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum) in comparison to an already known comparable bearing (cf. curve for Friction Pendulum);

(16) FIG. 5D shows schematically a diagram in which the course of the re-centering error (residual total bearing displacement) as a function of the peak ground acceleration (PGA) of a sliding pendulum bearing dimensioned in accordance with the second embodiment of the dimensioning method (cf. curve for MAURER Adaptive Pendulum) in comparison with an already known comparable bearing (cf. curve for Friction Pendulum);

DETAILED DESCRIPTION

(17) FIGS. 2 and 3 show the schematic structure of a sliding pendulum bearing 5 corresponding to a particularly advantageous embodiment of this invention. Similar to the double with joint described above with reference to FIG. 1C, the sliding pendulum bearings 5 shown comprise a first sliding plate 1 with a first main sliding surface 10, a second sliding plate 2 with a second main sliding surface 20, a slider 3 divided into two slider parts 3a and 3b and various sliding elements 4 and 4a. The first slider part 3a is in surface contact with the first main sliding surface 10 of the first sliding plate 1 via a sliding element 4, while the second slider part 3b is in surface contact with the second main sliding surface 20 of the second sliding plate 2 via another sliding element 4. The two slider parts 3a and 3b are in surface contact with each other via the sliding element 4a. The only difference between the design example shown in FIG. 3 and the design example shown in FIG. 2 is that the sliding pendulum bearing 5 shown in FIG. 3 has a limitation means 6 on the second sliding plate 2, which limits the displacement capacity of the slider 3 on the second main sliding surface 20 and is designed here in particular as a limiting ring.

(18) At this point, it should be made clear that limitation means 6 is particularly advantageous for certain load cases, but is not necessarily necessary for the formation of a sliding pendulum bearing in accordance with the present invention. It must also be made clear that the limitation means 6 does not limit the total displacement capacity of the bearing, since the limitation means 6 limits the maximum movement at one of the two main sliding surfaces to a maximum.

(19) As already described above, the sum of the effective radii of curvature of its main sliding surfaces 10 and 20 corresponds to the effective radius of curvature of the first main sliding surface 10 of a Double type sliding pendulum bearing with joint. Furthermore, the coefficients of friction of the two main sliding surfaces 10 and 20 of the Double with Hinge are identical to each other. This means that both main sliding surfaces 10 and 20 of the double with joint are structurally identical and thus both main sliding surfaces 10 and 20 are designed for the same load case. This serves to evenly divide a bearing movement occurring in the sliding pendulum bearing between the two main sliding surfaces 10 and 20, which results in approximately half of the horizontal installation space required by a single.

(20) In contrast, the sliding pendulum bearings 5 shown in FIGS. 2 and 3 have the main sliding surfaces 10 and 20 designed for two different load cases. This means that, in contrast to the double with joint, the two main sliding surfaces 10 and 20 differ from each other at least in terms of their radius of curvature and/or their coefficient of friction.

(21) In the exemplary embodiments shown in FIG. 2 and FIG. 3, the radii of curvature and the coefficients of friction of the first main sliding surfaces 10 essentially correspond to the radius of curvature and the coefficient of friction of the first main sliding surface 10 of a corresponding single 5. Thus, the radius of curvature of the respective first main sliding surface is almost twice as large as that of a corresponding double with joint. Furthermore, the respective second main sliding surface 20 of the shown advantageous exemplary embodiments form 5 has an effective radius of curvature which essentially corresponds to the effective radius of curvature of the first main sliding surface 10 and is thus twice as large as the radius of curvature of the second main sliding surface 20 of a corresponding double with joint. The coefficient of friction of the respective second main sliding surface 20 is also considerably smaller than the coefficient of friction of the respective first main sliding surface 10 and lies in the range of the lubricated friction, i.e. in the range from 0.2% to 2%, here for example at 1.0%.

(22) Consequently, the sliding pendulum bearings 5 depicted in FIGS. 2 and 3 differ from a corresponding double with joint known from the state of the art in particular with regard to the values of the radii of curvature of the respective first main sliding surface 10 and the respective second main sliding surface 20 as well as with respect to the coefficient of friction of the respective second main sliding surface 20.

(23) The respective first main sliding surface 10 is designed for the peak ground acceleration value of the design basis earthquake, while the respective second main sliding surface 20 is designed for a peak ground acceleration value which is lower than that of the design basis earthquake.

(24) If one of the sliding pin bearings 5 schematically shown in FIGS. 2 and 3 is now excited, the slider 3 will first move along the respective second main sliding surface 20 over the second sliding plate 2 (e.g. to the left), while essentially maintaining its position relative to the respective first sliding plate 1.

(25) With the sliding pendulum bearing 5 with limitation means 6 on the main sliding surface 20, approximately the following happens (see FIG. 3): As soon as the slider 3 reaches the limitation means 6, the slider cannot move further in this direction (i.e. to the left) along the glide plate 2, so that, with sufficient excitation strength, a movement of the slider 3 is now carried out along the first main glide surface 10 of the first sliding plate 1 until the reversal point of the excitation is reached. As soon as the reversal point of the excitation is reached and the excitation is reversed in the opposite direction, the slider 3 is first moved along the second main sliding surface 20 of the sliding plate 2 (to the right) up to the other side of the limitation means 6. As soon as the slider 3 has reached the limitation means 6 again, its movement is no longer possible in relation to the second sliding plate 2. From then on the remaining excitation is intercepted by a movement of the slider 3 along the first main sliding surface 10 of the first sliding plate 1. This play is repeated until no more excitation takes place and the slider aligns itself advantageously again in or as close as possible to the respective centre of the two sliding plates 2 and 1.

(26) With the sliding pendulum bearing 5 without limitation means on the main sliding surface 20, approximately the following happens (see FIG. 2): The slider will also move relative to the second main sliding surface 20 as soon as the friction force on the second main sliding surface 20 is equal to the dead force of the first main sliding surface 10, which is the sum of the friction force on the second main sliding surface 20 and the slope driven force from the curvature of the main sliding surface 20. This state of motion can also occur with the sliding pendulum bearing 5 with limiting ring, depending on the design of the effective radii and coefficients of friction of the two main sliding surfaces 10 and 20. In this case, the slider will only arrive at the limitation means of the main sliding surface 20 at a later point in time. The main difference between the sliding pendulum bearing 5 with limitation means and the sliding pendulum bearing 5 without limitation means is that the former leads to a somewhat smaller maximum bearing movement at the maximum credible earthquake than the latter, but the isolation of the former is slightly less good than that of the latter, but still considerably better than that of the conventional sliding pendulum bearing type Single or Double.

(27) Contrary to the bearing movement of the bearing according to the invention, which is limited mainly to one of the two sliding plates, the conventional double with joint distributes any bearing movement occurring uniformly throughout the two main sliding surfaces 10 and 20. This leads to a poorer isolation behaviour for most of the possible peak ground accelerations of the possible earthquakes. The design of the main sliding surfaces 10 and 20 for different load cases ensures that the corresponding sliding pendulum bearing 5 is not only designed for a peak ground acceleration value, but for a large range of possible peak ground acceleration values, and thus exhibits an overall isolation behavior that is closer to the sliding pendulum bearing with optimized viscous damping and consequently better over a large range of possible peak ground acceleration values.

(28) In the following, two examples of dimensioning methods for corresponding sliding pendulum bearings are presented and the resulting sliding pendulum bearing is compared with a corresponding conventional sliding pendulum bearing of the type Single.

(29) First, a design of the parameters of the sliding pendulum bearing based on the design of a corresponding single is carried out. The radius of curvature R.sub.eff,1 of the first main sliding surface is calculated from the intended isolation cycle duration T.sub.ISO according to the formula
R.sub.eff,1=g(T.sub.ISO/2).sup.2

(30) The radius obtained from this corresponds to the radius of the first main sliding surface of a corresponding single.

(31) The coefficient of friction .sub.1 for the first main sliding surface with the radius R.sub.eff,1 is then determined under the assumption of a single for the peak ground acceleration value of the assumed design basis earthquake by means of dynamic simulation with optimization to minimum absolute construction acceleration. Alternatively, the coefficient of friction .sub.1 for the first main sliding surface could also be determined using the linear method of the response spectrum. Now the radius R.sub.eff,2 of the second main sliding surface is selected equal to the radius R.sub.eff,1 of the first main sliding surface and the coefficient of friction .sub.2 of the second main sliding surface is set with a value typical for lubricated friction. Furthermore, the maximum movement capacity of the slider on the two main sliding surfaces is calculated for the maximum credible earthquake.

(32) These steps serve a rough design of the parameters of the sliding pendulum bearing and are identical for the two examples of the design method described here according to the invention.

(33) For this first design of the main sliding surface of the sliding pendulum bearing, the corresponding values for a sliding pendulum bearing of type Single are used.

(34) In the examples shown here, it is assumed that the peak ground acceleration value of the design basis earthquake is 4 m/s.sup.2 and the peak ground acceleration value of the maximum credible earthquake is 6 m/s.sup.2, i.e. 150% of the peak ground acceleration value of the design basis earthquake. Furthermore, an isolation cycle duration of 3.5 seconds should be maintained. The optimization of the coefficient of friction .sub.1 of the first main slip surface 10 for a minimum absolute construction acceleration of 4 m/s.sup.2 at the peak ground acceleration results in a coefficient of friction of 3.0% in the present example. The movement capacity of d=0.3 m required for the first main sliding surface 10 can be estimated from the movement capacity of the Single type for the peak ground acceleration value of the maximum credible earthquake.

(35) After the first rough design of the sliding pendulum bearing, the intended main sliding surfaces must be matched to each other in such a way that the sliding pendulum bearing meets certain boundary conditions. For the first example, the aim is to achieve an almost linear isolation behavior with minimum absolute construction accelerations.

(36) Starting from the first design, the second effective radius of curvature R.sub.eff,2 is first set equal to the first effective radius of curvature R.sub.eff,1 and the second coefficient of friction .sub.2 is set to a value of lubricated friction in the range from 0.2% to 2% and in this example to 0.75%.

(37) After this first design, the coefficient of friction .sub.1 of the first main sliding surface, the effective radius R.sub.eff,2 of the second main sliding surface and the movement capacity of the slider on the second main sliding surface D.sub.2 are varied until, over the entire range of the relevant peak board acceleration values, at least on average, the smallest possible absolute construction acceleration is achieved and the isolation behaviour is as linear as possible. Finally, the required movement capacity D.sub.1 of the slider on the first main sliding surface is determined, which results in particular from the peak ground acceleration value of the maximum credible earthquake.

(38) In the present example, this optimization shows that the coefficient of friction .sub.1 of the first main sliding surface is 3.5%, the two radii of curvature R.sub.eff,1 and R.sub.eff,2 of the two main sliding surfaces are identical and correspond to the radius of curvature of the corresponding single, the coefficient of friction .sub.2 of the second main sliding surface is 0.85% and the necessary movement capacity of the slider on the second main sliding surface D.sub.2 is 0.130 m. The limitation of the slider's movement capacity on the second main sliding surface is achieved structurally by a limitation means provided in the sliding pendulum bearing.

(39) FIGS. 4A to 4D finally show diagrams in which the behavior of the sliding pendulum bearing designed according to the design method described above is compared to the behavior of a corresponding single and a corresponding sliding pendulum bearing with optimized viscous damping.

(40) FIG. 4A shows the absolute construction acceleration as a function of the peak ground acceleration (PGA). When comparing the corresponding curves with each other, it can be seen that the sliding pendulum bearing obtained according to the design method described above (cf. curve for Maurer Adaptive Pendulum) has an almost linear curve of the absolute construction acceleration as a function of the peak ground acceleration. Furthermore, the corresponding values for the absolute structural acceleration are clearly below the respective values of the corresponding Single type sliding pendulum bearing (see curve for Friction Pendulum). In addition, it can be seen that the values obtained for the absolute construction acceleration for the sliding pendulum bearing designed according to the embodiment are on average much closer to the values of the sliding pendulum bearing with optimized viscous damping (cf. curve to Pendulum with optimized viscous damping) than the respective values for the corresponding single. Consequently, the sliding pendulum bearing dimensioned according to the embodiment of the present invention has a better isolation behaviour than a corresponding single, so that stresses on the construction can be better suppressed by the sliding pendulum bearing dimensioned according to the invention.

(41) FIG. 4B shows the maximum horizontal bearing force occurring for the corresponding bearings as a function of the peak ground acceleration. The corresponding curves closely resemble the corresponding curves shown in FIG. 3A, so that the findings obtained above with reference to FIG. 3A can essentially also be transferred to the maximum horizontal bearing forces.

(42) The diagram in FIG. 4C shows the maximum bearing movement as a function of the peak bearing acceleration value for the corresponding bearings. It can be seen that the maximum bearing movement due to the maximum credible earthquake for the bearing designed according to the invention is considerably smaller than the value of the conventional sliding pendulum bearing of type Single or Double.

(43) FIG. 4D shows the back centering error for the bearings described above as a function of the peak ground acceleration. From the diagram it can be seen that for the correspondingly designed sliding pendulum bearing, a back centering error of slightly more than 10% results, especially for the value for the peak ground acceleration of 3 m/s.sup.2. Thus, for this peak ground acceleration value, the back centering error of the sliding pendulum bearing dimensioned according to the present embodiment of the invention is higher than for the corresponding single or for the sliding pendulum bearing with optimized viscous damping. However, the back centering error does not exceed the limit of 50% and is even far below this limit value. This increased back centering error is more than compensated by the above described optimized behaviour of the sliding pendulum bearing designed according to the present embodiment with respect to the maximum absolute construction acceleration, the maximum bearing force and the maximum bearing movement and is far below the limit value of 50%, which means that the comparatively insignificant deterioration is gladly accepted here.

(44) For the second design example of the dimensioning method according to the invention, the aim is not to obtain any bearing movement at low loads and to obtain an approximate linear behaviour with minimum absolute structural acceleration for loads with higher peak ground acceleration values.

(45) Starting from the first design of the sliding pendulum bearing described above on the basis of the values resulting for a corresponding sliding pendulum bearing of type Singles, the second effective radius of curvature R.sub.eff,2 is set equal to the first effective radius of curvature R.sub.eff,1 and the second coefficient of friction .sub.2 is set to the value 3.0% in order to guarantee the required minimum shear resistance of 3% of the vertical load on the bearing (identical to 3% of the absolute acceleration in g).

(46) In the course of a coordination of the properties of the two main sliding surfaces, the two coefficients of friction .sub.1 and .sub.2, the radius of curvature R.sub.eff,2 of the second main sliding surface and the movement capacity of the slider on the second main sliding surface are then designed under the boundary conditions that the sliding pendulum bearing is not to be triggered up to a certain excitation and that the sliding pendulum bearing is to produce an approximately linear behaviour of the absolute construction acceleration as a function of the peak ground acceleration. This optimization is also carried out by dynamic simulation of the construction with sliding pendulum bearings.

(47) In the present case, the results of the optimization show that the coefficient of friction .sub.1 of the first main sliding surface and the coefficient of friction .sub.2 of the second main sliding surface must be 3.0%, while the effective radii of the first main sliding surface and the second main sliding surface R.sub.eff,1 and R.sub.eff,2 are both equal to the effective radius of the corresponding single. A limitation of the slider's movement capacity on the second main glide surface is not necessary.

(48) Analogous to FIGS. 4A to 4D, FIGS. 5A to 5D show the maximum absolute construction acceleration, the maximum bearing force, the maximum bearing movement and the back centering error as a function of the peak ground acceleration.

(49) As can be seen from the diagrams in FIGS. 5A and 5B, the values for the maximum absolute construction acceleration as well as for the maximum bearing force for the sliding pendulum bearing dimensioned according to the second embodiment (cf. curves for Maurer Adaptive Pendulum) are significantly lower than for the corresponding sliding pendulum bearing of type Single (cf. curves for Friction Pendulum). This means an improved isolation behavior of the sliding pendulum bearing designed according to the second embodiment compared to the corresponding Single.

(50) The diagram in FIG. 5C shows that the maximum occurring bearing movements for the sliding pendulum bearing dimensioned in accordance with the second design example for small peak ground acceleration values are essentially identical with the maximum bearing movements of the corresponding single, but that considerably lower maximum bearing movements are achieved, especially with higher values for peak ground acceleration. Smaller bearing movements make it possible to provide less installation space for the corresponding sliding pendulum bearing and thus, in addition to reducing the cost of manufacturing the sliding pendulum due to lower material costs, also ensure more efficient utilization of the accessible installation space.

(51) The diagram shown in FIG. 5D shows that the improvements with regard to the maximum absolute construction accelerations and the maximum occurring bearing forces lead to an increase in the back centering errors. However, the occurring back centering errors for all relevant peak ground acceleration values are clearly below the limit of 50% and only slightly above the values for the corresponding sliding pendulum bearing type Single. However, this slight increase in the back centering error is more than compensated by the improvement in the isolation behaviour of the sliding pendulum bearing in relation to the maximum absolute construction accelerations and the maximum bearing forces occurring.

(52) Of course, other specifications for the adjustment or optimization of the two main sliding surfaces are also possible, which make it possible to adapt the resulting sliding pendulum bearing to a large number of different requirements considerably better than the conventional sliding pendulum bearing and to realize a number of advantages, such as lower manufacturing costs, a smaller required installation space and lower maintenance costs.

(53) This results in a multitude of adjustment and optimization possibilities for both the design of the sliding pendulum bearing itself and for the corresponding dimensioning method.

LIST OF REFERENCE CHARACTERS

(54) 1: first sliding plate 2: second sliding plate 3: slider 3a, 3b, 3c, 3d: slider part 4, 4a, 4b: sliding element 5: sliding pendulum bearing 10: first main sliding surface 20: second main sliding surface