Startseite Advancing seismic performance: Isolators, TMDs, and multi-level strategies in reinforced concrete buildings
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Advancing seismic performance: Isolators, TMDs, and multi-level strategies in reinforced concrete buildings

  • Fadhil A. Jasim ORCID logo EMAIL logo , Nabeel A. Jasim ORCID logo und Abdullah A. Al-Hussein ORCID logo
Veröffentlicht/Copyright: 6. April 2024
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Abstract

This study evaluates seismic mitigation methods, including high damping rubber bearing, lead rubber bearing, double sliding pendulum (DSP), and tuned mass damper (TMD), considering earthquake intensity, building height, and isolation level. Moreover, the study delves into a novel approach that incorporates multi-level isolation and multi-level TMD. Reinforced concrete buildings, ranging in height from 4 to 40 storeys, were nalysed and nalysed using SAP2000 under the seismic influence of the Badra, El Centro, and Northridge earthquakes. The study reveals a significant rise in the fundamental period (T) with base isolation systems, reaching 378% of the fixed base value for a six-storey building. Building height directly affects T values, with simplified equations introduced for calculation. DSP proves 5% more efficient in reducing base shear (BS), while TMD is effective in weaker earthquakes for minimizing lateral displacement. Base isolators outperform mid-level isolation and TMD at the top storey. Combining base isolators with TMD at the top storey is deemed impractical and uneconomical. The study recommends multilevel isolation or multilevel TMD for enhanced seismic isolation efficiency, with four-level isolation achieving an 80% reduction in BS for 12-storey buildings. In addition, four-level TMD outperforms TMD at the top storey with a 44.5% reduction in BS, surpassing the 26.6% reduction achieved with TMD at the top storey only.

Keywords: base isolation; multi-level isolation; seismic isolation; tunned mass damper; seismic response

1 Introduction

Generally, the earth structure consists of inner core, outer core, mantle, and crust. The crust and the upper part of the mantle layer form the tectonic plates. There are seven large and several smaller plates [1]. The boundaries between these plates are named faults. These plates move relatively to each other [2]. As tectonic plates move, they can get stuck at their edges due to friction. Stress builds up in these areas, and when it exceeds the rocks’ strength, a sudden release of energy causes an earthquake or seismic wave. The size and severity of an earthquake are estimated by intensity and magnitude [3,4].

Earthquakes can be destructive to people and economy as well. It is found that around 10,000 people die every year due to earthquakes. Also, many towns and villages were destroyed around the world [5].

Since earthquake events cannot be predicted or avoided, implementing measures to minimize damage and protect communities becomes crucial. Many seismic construction design and technology have been developed to reduce the effect of earthquakes on the structures. In traditional methods, the building’s resistance to earthquakes is provided by either high strength and rigidity or high ductility of the structure. Increasing the structure’s stiffness reduces the vibration period, causing a rise in acceleration and amplified seismic loads. Concurrently, higher ductility contributes to an increase in interstory drift demands [6,7]. The negative side of this method is that the building has to absorb all the lateral forces induced by the seismic ground motion. A modern method was developed to overcome the disadvantage of the traditional method by isolating the structure from the earthquake effect by using flexible material at the horizontal level called isolators (Figure 1) [3]. Base isolators come primarily in two major types: elastomeric bearings and friction pendulum systems (Figure 2) [8]. Using the isolation systems increases the superstructure’s period much longer than its fixed-base natural period. This can reduce the pseudo-acceleration and the induced forces in the structure, but at the same time, the deformation may be increased. This deformation is concentrated in the isolation system; therefore, only small deformations in the structure occur [9,10,11].

Figure 1 Fixed and base isolated structures [3]. (a) Conventional earthquake-resistant building. (b) Building with base isolation pads.
Figure 1

Fixed and base isolated structures [3]. (a) Conventional earthquake-resistant building. (b) Building with base isolation pads.

Figure 2 Common base isolators [8]. (a) Elastomeric bearing with steel shims. (b) Lead-plug bearing. (c) Friction pendulum bearing. (d) Friction pendulum bearing with double concave surface.
Figure 2

Common base isolators [8]. (a) Elastomeric bearing with steel shims. (b) Lead-plug bearing. (c) Friction pendulum bearing. (d) Friction pendulum bearing with double concave surface.

Base isolation has gained popularity due to advancements in isolator production. Various types of isolators and techniques are now available for consideration during the building design stage [12,13].

Many previous studies investigated the efficiency of different base isolation systems. The seismic behaviour of a low-rise base isolated building in Italy was explored by Braga and Laterza [14]. The isolators were high damping rubber bearing (HDRB). The study proved the efficiency of these isolators in reducing the seismic response of the studied buildings. Symmetrical and horizontally and vertically irregular reinforced concrete buildings with fixed and base isolated were studied by Al-Jubair and Majeed [15] to show the efficiency of base isolated technique. The isolators were HDRB and friction pendulum (FP) having the same fundamental period and design displacement. It was found that both HDRB and FP isolators can be used with high efficiency. The effect of isolator location on 10-storey reinforced concrete buildings was studied by Seranaj and Garevski [16]. It was found that the base isolation gave better performance than middle storey isolation. The study conducted by Komur [17] demonstrated that the fundamental period was increased due to using lead rubber bearing (LRB) as a base isolator for reinforced concrete building. Also, the storey drift was minimized. Abed et al. [18] showed that the behaviour of friction isolator is related to the low value of peak ground acceleration-to-peak ground velocity ratio. Momeni and Bagchi [19] developed seismic control devices to enhance the performance of the structure. On the other hand, using the tunned mass damper (TMD) at the top of six-storey reinforced concrete building reduced the seismic response of the building. The base shear (BS) was reduced by about 10–30% [21].

This study aims to investigate the optimal isolator type for enhancing the fundamental period and reducing BS, top storey displacement (TSD), storey drifts and top story acceleration. It conducts a thorough comparison of isolator efficiency with TMD. In addition, the study evaluates the effectiveness of a recently developed system that integrates both base isolators and TMD. The impact of varying building heights and earthquake intensities on the efficiency of base isolators and TMD is thoroughly investigated. Simultaneously, the study delves into the efficiency of multilevel isolation and multilevel TMD configurations.

2 Building description

To demonstrate the effectiveness of the isolators and mass dampers, multistorey reinforced concrete office buildings with a range of 4–40 storeys are considered in this study. The plan for the studied symmetric office building is shown in Figure 3, and the elevation view of six-storey building is shown in Figure 4. The reinforced concrete building cross-sections details are presented in Table 1. The reinforced concrete slab has a thickness of 150 mm. The base of the building is either fixed or isolated by using the isolators. The soil structure interaction is not considered.

Figure 3 Plan of the building.
Figure 3

Plan of the building.

Figure 4 Elevation view of six-storey building.
Figure 4

Elevation view of six-storey building.

Table 1

Geometry of building

Element Dimensions (mm) Reinforcement Storey range*
Column (C1) 400 × 300 10 Ø 25 1st 5 storeys
Column (C2) 500 × 300 12 Ø 25 2nd 5 storeys
Column (C3) 600 × 300 14 Ø 25 3rd 5 storeys
Column (C4) 600 × 400 16 Ø 25 4th 5 storeys
Column (C5) 600 × 500 16 Ø 25 5th 5 storeys
Column (C6) 700 × 500 20 Ø 25 6th 5 storeys
Column (C7) 800 × 500 20 Ø 25 7th 5 storeys
Column (C8) 800 × 600 24 Ø 25 8th 5 storeys
Beams 200 × 500 4 Ø 20 T&B All storeys

*Storeys range measured from the top storey.

3 Applied loads and ground motions

The applied loads are defined in according to the International Building Code 2021 (IBC 2021) [22]. In addition to the self-weight, 2 kN/m2 is applied to each floor surface as a dead load resulting from the finishing materials. The roof live load is taken as 1.5 kN/m², and the floor live load is taken as 2.5 kN/m² for offices and 4 kN/m² for corridors. The outside walls are made from thermiston bricks. The partition load is 0.72 kN/m2, considered a uniform distributed live load. All dead load and only 25% of the live load are considered in the seismic analysis.

Three earthquakes are considered in this study. They are Badra (Iraq-Iran boundaries, 2009), El Centro (Los Angeles USA, 1940), and Northridge (California USA, 1994). The time history data of these earthquakes are shown in Figures 5–7 [23,24].

Figure 5 Badra (Iraq-Iran border) earthquake [23].
Figure 5

Badra (Iraq-Iran border) earthquake [23].

Figure 6 Northridge earthquake (Sepulveda VA Hospital, R rup = 8.44 km) [24].
Figure 6

Northridge earthquake (Sepulveda VA Hospital, R rup = 8.44 km) [24].

Figure 7 El Centro earthquake (El Centro Array #9, R rup = 6.09 km) [24].
Figure 7

El Centro earthquake (El Centro Array #9, R rup = 6.09 km) [24].

4 Base isolation systems

The HDRB, LRB, and double sliding pendulum (DSP) isolators are used to isolate the building from seismic effect. The three used isolators in this study are designed to provide adequate damping to dissipate the energy during an earthquake with a practical displacement (Appendix). Also, they should have high vertical stiffness to support the vertical loads and sufficient horizontal stiffness to make the building stable under service lateral loads.

The input and output parameters used to isolate six-storey building are given in Table 2 and defined as follows:

Table 2

Properties of base isolators (six-storey building)

Property HDRB LRB DSP
T D (s) 2.5 2.5 2.5
D (mm) 200 200 200
K v (kN/m) 4,300,000 1,970,000 1,360,000
K eff (kN/m) 1,400 1,370 1,360
Q (kN) 113 141 47
K 2 (kN/m) 829 663 1,125
D y (mm) 15.1 17.7 0.42
β (%) 24 30 23
r 0.1 0.077 0.1
R (m) 2

T D, design period; D, design displacement; K v, vertical stiffness; K eff, effective horizontal stiffness; Q, characteristic strength or yield strength; K 2, inelastic stiffness or post-yield stiffness; β, effective damping; K 1, elastic stiffness or initial stiffness; D y, yield displacement; R, radius of curvature of the sliding surface.

5 TMD

It is a well-known type of active seismic isolation system. A typical application of a tuned mass damper consists of a heavy mass installed near a building’s top in such a way that it tends to remain still while the building moves beneath it. This strategy allows the mass at the top to transmit its inertial force to the building in a direction opposite to the motions of the building itself, thereby reducing the building’s oscillations [25].

The pendulum TMD system can be represented by a mass supported by cables, which allow the system to behave as a pendulum. Figure 8 shows a simple pendulum attached to a floor. The properties of the system are defined as follows: L is the cable or spring length, u is the displacement, K H is the equivalent stiffness of the cable, and m d is the mass of damper [26].

Figure 8 Simple pendulum tuned mass damper [26]; (a) actual system and (b) equivalent system.
Figure 8

Simple pendulum tuned mass damper [26]; (a) actual system and (b) equivalent system.

Different values for m d and L are investigated to select the best m d and L, which give the minimum BS and TSD. The considered TMD properties in this study are listed in Table 3.

Table 3

Properties of the used TMD

Property Value
Spring length (L) 1 m
Vertical stiffness ( K V ) 490,000 kN/m
Damping constant (C) 0.07
Damper weight/total building weight% (W d/W t%) 1.3
Horizontal stiffness (K H) 366 kN/m

6 Numerical modelling

In this study, SAP2000-V24 is used to model and analyse all the studied cases. Frame elements are used to define the beams and columns. Shell elements are used to model the slabs. Link/support elements are used to model the isolators. The optimum mesh size is found to be 0.25 m × 0.25 m for slabs and 0.25 m length for all beams and columns.

The nonlinear properties of the isolation systems are represented by the bilinear hysteretic model as shown in Figure 9. These properties are defined in SAP2000 as shown in Figure 10.

Figure 9 Characteristics of bilinear seismic isolation [27].
Figure 9

Characteristics of bilinear seismic isolation [27].

Figure 10 Isolator properties.
Figure 10

Isolator properties.

The configuration of the studied building with TMD is shown in Figure 11. The mass damper is modelled as a linear link with one end fixed at the top storey and the other end free. The mass weight is assigned at the free end.

Figure 11 Building with TMD.
Figure 11

Building with TMD.

7 Results and discussion

7.1 Efficiency of base isolation systems and TMD

The nonlinear modal time history analysis method is used to analyse the fixed base (FB) and isolated base (IB) buildings with and without TMD at the top storey. Three systems of isolators (HDRB, LRB, and DSP) located at the base of ground floor columns are studied. A six-storey reinforced concrete building subjected to the N–S component of El Centro earthquake is considered to investigate the efficiency of the isolation systems. The results of fundamental period (T), BS, base shear reduction (BSR), TSD, base displacement (BD), and top storey acceleration (TSA) are presented in Table 4.

Table 4

Efficiency of base isolation systems and TMD

Isolation system T (s) BS (kN) BSR% TSD (mm) BD (mm) TBD (mm) TSA (m/s2)
FB 0.52 12069 112.3 112.3 8.3
IB (HDRB) 2.475 3248 73 146 129.5 16.5 2.91
IB (LRB) 2.477 3314 72.5 166 149 17 2.96
IB (DSP) 2.488 1865 84.5 140.3 127.8 12.5 2.83
FB + TMD 1.052 8931 26 54.2 0 54.2 5.67
IB (HDRB) + TMD 2.461 2925 76 117 103.6 13.4 3.51
IB (LRB) + TMD 2.46 3020 75 141.5 126.2 15.3 3.57
IB (DSP) + TMD 2.464 1419 88 102 93.5 8.5 3.04

It is found that using all the base isolation systems leads to an increase in T by around 378%. Also, HDRB and LRB reduce the BS by about 73%, while the DSP reduces the BS by 84.5%. Figure 12 depicts the time variation of BS for fixed-base and DSP IB buildings. Hence, using DSP isolators is preferred over HDRB and LRB.

Figure 12 BS for FB and DSP IB buildings (El Centro).
Figure 12

BS for FB and DSP IB buildings (El Centro).

The investigated isolation systems remain unaffected by earthquake intensity, consistently achieving BSR within the range of 70–90%. Consequently, base isolation techniques prove effective in safeguarding buildings from any earthquake event (Figure 13). Using TMD reduces BS of FB building by 38% when the building is subjected to weak earthquake (Badra), while the BSR is around 9% only when the building is subjected to strong earthquake such as Northridge. This indicates that TMD is less efficient than base isolation systems, as illustrated in Figure 14. It might be considered to enhance the seismic response of buildings exposed to weaker earthquakes.

Figure 13 BS values for different earthquakes.
Figure 13

BS values for different earthquakes.

Figure 14 BS for HDRB IB building and FB building with TMD (El Centro).
Figure 14

BS for HDRB IB building and FB building with TMD (El Centro).

The TSA can be reduced by about 66% when using base isolators (Figure 15). show that the TSD for the isolated buildings is increased as compared with FB buildings but this increase in TSD is mainly concentrated in the isolator’s level. On the other hand, it is found that modeling the TMD at the top of six-storey building with FB reduces the TSD or total building drift (TBD) from 112.3 to 54.2 mm, but this reduction is still low compared to that obtained in the case of using base isolators. Therefore, TMD may serve as a practical choice for buildings with limited lateral movement space.

Figure 15 TSA for FB and DSP IB buildings (El Centro).
Figure 15

TSA for FB and DSP IB buildings (El Centro).

Figure 16 TSD for FB and DSP IB buildings (El Centro).
Figure 16

TSD for FB and DSP IB buildings (El Centro).

Figure 17 TSD for different earthquakes.
Figure 17

TSD for different earthquakes.

Also, it is detected that the building moves as a rigid body where the storey drift (TSD – BD) is very small as compared with the FB case (Figures 18–20).

Figure 18 Deformation model of FB and DSP isolated buildings (El Centro).
Figure 18

Deformation model of FB and DSP isolated buildings (El Centro).

Figure 19 Lateral displacement for FB and isolated buildings (El Centro).
Figure 19

Lateral displacement for FB and isolated buildings (El Centro).

Figure 20 TBD for different earthquakes.
Figure 20

TBD for different earthquakes.

Conversely, the results shown in Table 4 indicate that the utilization of a novel system incorporating both base isolation and TMD at the top storey leads to a mere 3% increase in BSR. Furthermore, BD and TSD exhibit a reduction of 20–27% compared to values obtained from base isolation systems. Thus, this system combines the advantages of base isolation systems and TMD, rendering it a practical choice for buildings with restricted lateral space necessary for the movement of base-isolated structures.

7.2 Effect of building height

To study the relationship between building height and seismic response of FB and IB buildings, 11 buildings subjected to El Centro earthquake were modelled. The buildings have the same slabs and beam sizes, while the columns sections are changed depending on the building height as presented in Table 1. The buildings height varies from 4 storeys (13 m) to 40 storeys (121 m).

It is clearly found that the natural vibration period (T) of FB and base isolated buildings has a direct relationship with the number of storeys or building height (Figure 21).

Figure 21 Relationship between the number of storeys and T.
Figure 21

Relationship between the number of storeys and T.

New formulas have been proposed to calculate the fundamental period (T) values for diverse building heights and under various base conditions. They are based on the building height (H) or the number of storeys (N), given as follows:

(1) T ( FB ) = 0.18 N 3 / 4 for N < 10 storey , Else = 0.21 N 3 / 4 ,

(2) T ( FB ) = 0.075 H 3 / 4 for H < 31 m , Else = 0.09 H 3 / 4 ,

(3) T ( IB ) = ( T D − 0.5 ) + 0.075 N ,

(4) T ( IB ) = ( T D − 0.5 ) + 0.025 H .

These equations are verified against previous studied, and the results are presented in Tables 5 and 6.

Table 5

Fundamental period of FB buildings

No. of storeys T (s)
FE Equation (1) Previous studies [Ref.]
4 0.41 0.51 0.39 [28] 0.562 [30] 0.4 [37]
5 0.57 0.60 0.641 [33]
6 0.52 0.69 0.57 [28] 0.625 [29] 0.6 [37]
7 0.78 0.77 0.829 [33]
8 0.83 0.86 0.81 [28] 1.083 [30] 0.8 [37]
9 0.95 0.94 0.997 [33]
10 1.11 1.18 1.14 [32] 1.16 [35]
12 1.32 1.35 1.159 [33]
15 1.63 1.60 1.426 [29]
20 2.16 1.99 1.71 [36] 1.887 [31] 1.96 [35]
25 2.43 2.35 2.22 [36]
30 2.71 2.69 2.58 [35]
35 3.11 3.02 3.37 [36] 3.323 [34]
40 3.38 3.34 3.721 [34]
Table 6

Fundamental period of IB buildings

No. of storeys T D (s) T (s)
FE Equation (3) Previous studies [Ref.]
3 4 3.755 4.007 [38]
4 1.5 1.3 1.523 [29]
2 1.8 2.05 [39]
2.5 2.15 2.3 2.23 [30] 2.55 [39]
6 2 1.95 2.15 [12]
2.5 2.48 2.45 2.455 [30] 2.545 [31] 2.5 [39]
8 2 2.75 2.1 2.35 [39] 2.35 [30]
2.5 2.6 2.78 [39]
9 4 4.175 4.07 [38]
3 3.175 3.09 [38]
10 3 2.92 3.25 2.97 [12]
2.5 2.75 2.67 [12]
2 2.25 2.65 [32]
12 3 3.22 3.4
15 3 3.64 3.625 3.501 [29]
20 3.5 4.27 4.5 4.05 [30]
3 4 3.493 [31]
25 3.5 4.93 4.875
30 3.5 5.75 5.25
35 4 6.16 6.125
40 4 6.96 6.5

It is noticed that the BS values fluctuate with changing of building height (Figure 22). The increase in BS is associated with a low value for seismic response coefficient (Cs), which is defined as total seismic BS value (BS)/total effective seismic weight (W). Therefore, any increase in BS for tall building is mainly related to (W). The relationship between building height (number of storeys) and Cs is shown in Figure 23.

Figure 22 Relationship between building height and BS.
Figure 22

Relationship between building height and BS.

Figure 23 Relationship between Cs and building height.
Figure 23

Relationship between Cs and building height.

Simple formulas are suggested to calculate the (Cs) and BS for FB buildings depending on the number of storeys and building height. These equations provide a practical means to reduce both effort and time in the analysis process, given as follows:

(5) Cs = 2.5 N = 8 H ,

(6) BS = Cs × W .

Also, it is found that base isolation systems are efficient in reducing BS for all the studied earthquakes and building heights (Figure 24).

Figure 24 BS for different earthquakes and the number of storeys.
Figure 24

BS for different earthquakes and the number of storeys.

It is found that TSD is greater in tall FB buildings than in low-rise structures. The application of base isolation leads to an increase in TSD for low- and medium-rise buildings, while for tall buildings, it decreases compared to FB buildings (Figure 25). The TSD in base-isolated tall buildings is due to the higher horizontal stiffness of the utilized base isolators.

Figure 25 TSD and number of storey relationship.
Figure 25

TSD and number of storey relationship.

Generally, this increase in TSD is concentrated at isolator level where the total building drift (TBD = TSD − BD) is much lower than that found in the case of FB buildings (Figure 26).

Figure 26 Relationship between number of storeys and TBD.
Figure 26

Relationship between number of storeys and TBD.

The following equation is suggested to calculate the TBD for base isolated building:

(7) TBD = TSD − BD = 6 N 0.7 .

The aforementioned equation is verified by using some previous studies as given in Table 7.

Table 7

TBD of base isolated buildings

No. of storeys TBD (mm)
FE Equation (7) Previous studies [Ref.]
4 12.25 15.83 13.2 [30], 16 [43]
6 16.38 21.03 24 [31], 26 [40]
8 29.74 25.72 28.6 [30]
10 41.2 30.07 36 [32]
12 43.85 34.16 47 [40]
15 50.32 39.94
20 55.21 48.85 54 [31], 53 [32], 58 [41]
25 55 57.11
30 62.37 64.88
35 64.6 72.28
40 68.78 79.36

7.3 Multilevel isolation systems and TMD

The efficiency of one, two, three, and four isolation levels along a building height is investigated. A 12-storey building is considered to be subjected to El Centro earthquake in the N–S direction. The 11 cases studied are described in Table 8. The results of these cases are presented in Table 9.

Table 8

Case studies of multilevel isolation and TMD

Case study Description
Case 1 FB building without isolation and TMD
Case 2 Base isolated (HDRB)
Case 3 FB with isolator at middle (6th) storey (HDRB).
Case 4 Two-level isolated building (base (HDRB) + middle (6th) storey (HDRB))
Case 5 Three level isolated building (base (HDRB) + 4th storey (HDRB) + 8th storey (HDRB))
Case 6 Four levels isolated building (base (HDRB) + 3rd (HDRB) + 6th storey (HDRB) + 9th storey (HDRB))
Case 7 FB with TMD at top storey
Case 8 FB with TMD at middle (6th) storey
Case 9 FB with TMD at top storey and middle (6th) storey
Case 10 FB with TMD at top storey + 4th storey + 8th storey
Case 11 FB with TMD at (top storey + 3th storey + 6th storey + 9th storey)
Table 9

Results of multilevels isolation and TMD

Case no. T (s) BS (kN) BSR% TSD (mm) CDI* (mm) TSD-ID (mm) TSA (m/s)
1 1.52 11,495 0 166.4 0 166.4 5.78
2 3.22 4568.9 60.3 202.8 161.7 41.1 2.9
3 3.21 7756.3 32.5 234.4 151 83.4 3.14
4 3.02 3543.8 69.2 231.6 172.7 58.9 2.74
5 4.14 3130.2 72.8 230 183.4 46.6 2.36
6 4.28 2220.2 80.7 230.1 195 35.1 2.41
7 2.18 8442 26.6 112 0 112 5.55
8 2.18 8219 28.5 104.04 0 104.04 5.04
9 2.18 7785.6 32.3 90.9 0 90.9 4.84
10 2.18 6,687 41.8 81.9 0 81.9 4.67
11 2.18 6,381 44.5 76.6 0 76.6 4.64

CDI*: Summation of the lateral displacements of isolators occurred at all levels.

It is noticed that using multilevel isolation gives higher values to the natural vibration period (T). Also, it is identified that using TMD at multilevels has a negligible effect on (T).

On the other hand, it is observed that using the isolators in the middle of building with FB reduces the BS about 33%, while the base isolation with the isolators in the middle of building reduces the BS by around 70%. Also, it is found that using multilevel isolation reduces the BS more than using base isolation alone (Figure 27). The four-level isolation reduces the BS up to 81% (Figure 28). Consequently, employing a base isolation system demonstrates high efficiency, practicality, and economic feasibility compared to mid-level isolation systems.

Figure 27 Effect of multilevel isolation on (BS).
Figure 27

Effect of multilevel isolation on (BS).

Figure 28 BS for fixed and IB and four-level isolation.
Figure 28

BS for fixed and IB and four-level isolation.

Using TMD at middle of the building height with FB gives almost the same performance as that obtained from using TMD at the top storey. However, using TMD at multilevels leads to a decrease in the BS of the building (Figure 29). The BS is reduced by 44.5% in the case of using four levels of TMD, while it is reduced by 26.6% when only one TMD is used at the top storey of the building.

Figure 29 BS values for TMD at multilevels.
Figure 29

BS values for TMD at multilevels.

The multilevel isolation gives TSD values little higher than those obtained using base isolation only. This increase in TSD values is related to the displacement of the isolators at the different levels as shown in Figure 30.

Figure 30 Storey displacement and isolation levels.
Figure 30

Storey displacement and isolation levels.

Using TMD at multilevel leads to a decrease in the TSD as well as the storey drift as depicted in Figure 31. Generally, the storey drift values in cases of using TMD are higher than the values resulting from using an isolator at base only or at multilevels.

Figure 31 TSD of multilevel TMD.
Figure 31

TSD of multilevel TMD.

8 Conclusions

The study explores the effectiveness of three commonly used seismic isolators and TMD in reducing BS, lateral displacement, and top storey acceleration for low, medium, and tall buildings. In addition, a newly suggested system that combines base isolators and TMD as well as a multilevel isolation system are examined. The following conclusions can be drawn from this study:

  • The use of base isolation systems increases the fundamental vibration period by over 378% for six-storey buildings.

  • HDRB and LRB base isolation systems are equally effective in reducing seismic response, with the DSP system showing a slightly higher efficiency in minimizing BS. Hence, it is advisable to prioritize DSP during the design stage of base isolators.

  • The TBD is highly reduced by using base isolation system although the TSD may be increased, but this increase is concentrated at the isolation level.

  • The TMD shows a small efficiency in reducing the BS, top storey acceleration, and TBD as compared with the base isolation systems. It reduces the TSD more effectively than base isolators.

  • TMD demonstrates suitable efficiency in reducing BS resulting from weak earthquakes compared to strong earthquakes. Therefore, TMD and the system combines the base isolation and TMD are a practical choice for buildings with restricted lateral space and may be subjected to weak earthquakes.

  • A slight improvement is achieved by adding a TMD at the top storey of the base isolated buildings. Hence, employing a combined system of base isolators and TMD is neither practical nor economical.

  • The fundamental period of a building is directly related to its height. This relationship can be presented by simplified equations (equation (1)–(4)).

  • Employing a base isolation system demonstrates high efficiency, practicality, and economic feasibility compared to midlevel isolation systems.

  • Using base isolation increases the TSD of low- and medium-rise buildings and decrease the TSD in high-rise buildings as compared with FB buildings.

  • The TBD for all heights of base isolated building is very small compared with FB buildings and can be calculated by using the proposed formula, equation (7), with error percentage less than 30%.

  • The BS can be reduced by 81% using a four-level isolation system, surpassing the 60% reduction achieved with a base isolation system alone.

  • The BS can be reduced by 44.5% in the case of using four levels of TMD, while it was reduced by 26.6% in the case of using one TMD at top storey.

The presented results and equations are specific to reinforced concrete buildings. Further studies should explore other types of buildings and structures. In addition, investigating a combined active and passive system of seismic isolation could be considered.

  1. Funding information: Authors declare that the manuscript was done depending on the personal effort of the author, and there is no funding effort from any side or organization.

  2. Conflict of interest: The authors state no conflict of interest.

  3. Data availability statement: Most datasets generated and analysed in this study are comprised in this submitted manuscript. The other datasets are available on reasonable request from the corresponding author with the attached information.

Appendix

A1 Design of isolators

For the six-storey building, the maximum vertical load in service condition including seismic action (P v) is 2,250 kN, T D was assumed 2.5 s, and D was assumed 200 mm. The effective damping (β) for HDRB is taken 24%.

The horizontal or effective stiffness of the isolator is given by [1] and [3]:

K eff = W g 2 π T D 2 = 2 , 250 9.81 2 π 2.5 2 = 1 , 447 kN / m .

Then, the energy dissipation per one cycle is calculated as follows [1,3]:

EDC = 2 π K eff D 2 β eff = 2 π × 1 , 447 × 0.2 2 × 0.24 = 87.23 kN m .

By neglecting the yield displacement ( D y ), the characteristic strength is calculated as follows [1,3]:

Q = EDC 4 D = 87.23 4 × 0.2 = 109 kN .

The value for post yield stiffness is calculated as follows [1,3]:

K 2 = K eff − Q d D = 1 , 447 − 109 0.2 = 902 kN / m .

Then, by assuming ( K 1 = 10 K 2 ) [1,3]:

K 1 = 9 , 020 kN / m .

The yield displacement (D y) is calculated as follows [1,3]:

D y = Q K 1 − K 2 = 109 9 , 020 − 902 = 0.0134 m = 13.4 mm .

By considering the isolator catalogues, HDRB isolator is used with the following properties:

K eff = 1 , 400 kN / m , K 2 = 829 kN / m , D y = 15.1 mm , and β = 24 % .

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Received: 2023-12-14
Revised: 2024-01-11
Accepted: 2024-01-22
Published Online: 2024-04-06

© 2024 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

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https://doi.org/10.1515/eng-2022-0589
Schlagwörter für diesen Artikel
base isolation; multi-level isolation; seismic isolation; tunned mass damper; seismic response
Creative Commons
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  37. Applications of nanotechnology and nanoproduction techniques
  38. Relationship between indoor environmental quality and guests’ comfort and satisfaction at green hotels: A comprehensive review
  39. Communication
  40. Techniques to mitigate the admission of radon inside buildings
  41. Erratum
  42. Erratum to “Effect of short heat treatment on mechanical properties and shape memory properties of Cu–Al–Ni shape memory alloy”
  43. Special Issue: AESMT-3 - Part II
  44. Integrated fuzzy logic and multicriteria decision model methods for selecting suitable sites for wastewater treatment plant: A case study in the center of Basrah, Iraq
  45. Physical and mechanical response of porous metals composites with nano-natural additives
  46. Special Issue: AESMT-4 - Part II
  47. New recycling method of lubricant oil and the effect on the viscosity and viscous shear as an environmentally friendly
  48. Identify the effect of Fe2O3 nanoparticles on mechanical and microstructural characteristics of aluminum matrix composite produced by powder metallurgy technique
  49. Static behavior of piled raft foundation in clay
  50. Ultra-low-power CMOS ring oscillator with minimum power consumption of 2.9 pW using low-voltage biasing technique
  51. Using ANN for well type identifying and increasing production from Sa’di formation of Halfaya oil field – Iraq
  52. Optimizing the performance of concrete tiles using nano-papyrus and carbon fibers
  53. Special Issue: AESMT-5 - Part II
  54. Comparative the effect of distribution transformer coil shape on electromagnetic forces and their distribution using the FEM
  55. The complex of Weyl module in free characteristic in the event of a partition (7,5,3)
  56. Restrained captive domination number
  57. Experimental study of improving hot mix asphalt reinforced with carbon fibers
  58. Asphalt binder modified with recycled tyre rubber
  59. Thermal performance of radiant floor cooling with phase change material for energy-efficient buildings
  60. Surveying the prediction of risks in cryptocurrency investments using recurrent neural networks
  61. A deep reinforcement learning framework to modify LQR for an active vibration control applied to 2D building models
  62. Evaluation of mechanically stabilized earth retaining walls for different soil–structure interaction methods: A review
  63. Assessment of heat transfer in a triangular duct with different configurations of ribs using computational fluid dynamics
  64. Sulfate removal from wastewater by using waste material as an adsorbent
  65. Experimental investigation on strengthening lap joints subjected to bending in glulam timber beams using CFRP sheets
  66. A study of the vibrations of a rotor bearing suspended by a hybrid spring system of shape memory alloys
  67. Stability analysis of Hub dam under rapid drawdown
  68. Developing ANFIS-FMEA model for assessment and prioritization of potential trouble factors in Iraqi building projects
  69. Numerical and experimental comparison study of piled raft foundation
  70. Effect of asphalt modified with waste engine oil on the durability properties of hot asphalt mixtures with reclaimed asphalt pavement
  71. Hydraulic model for flood inundation in Diyala River Basin using HEC-RAS, PMP, and neural network
  72. Numerical study on discharge capacity of piano key side weir with various ratios of the crest length to the width
  73. The optimal allocation of thyristor-controlled series compensators for enhancement HVAC transmission lines Iraqi super grid by using seeker optimization algorithm
  74. Numerical and experimental study of the impact on aerodynamic characteristics of the NACA0012 airfoil
  75. Effect of nano-TiO2 on physical and rheological properties of asphalt cement
  76. Performance evolution of novel palm leaf powder used for enhancing hot mix asphalt
  77. Performance analysis, evaluation, and improvement of selected unsignalized intersection using SIDRA software – Case study
  78. Flexural behavior of RC beams externally reinforced with CFRP composites using various strategies
  79. Influence of fiber types on the properties of the artificial cold-bonded lightweight aggregates
  80. Experimental investigation of RC beams strengthened with externally bonded BFRP composites
  81. Generalized RKM methods for solving fifth-order quasi-linear fractional partial differential equation
  82. An experimental and numerical study investigating sediment transport position in the bed of sewer pipes in Karbala
  83. Role of individual component failure in the performance of a 1-out-of-3 cold standby system: A Markov model approach
  84. Implementation for the cases (5, 4) and (5, 4)/(2, 0)
  85. Center group actions and related concepts
  86. Experimental investigation of the effect of horizontal construction joints on the behavior of deep beams
  87. Deletion of a vertex in even sum domination
  88. Deep learning techniques in concrete powder mix designing
  89. Effect of loading type in concrete deep beam with strut reinforcement
  90. Studying the effect of using CFRP warping on strength of husk rice concrete columns
  91. Parametric analysis of the influence of climatic factors on the formation of traditional buildings in the city of Al Najaf
  92. Suitability location for landfill using a fuzzy-GIS model: A case study in Hillah, Iraq
  93. Hybrid approach for cost estimation of sustainable building projects using artificial neural networks
  94. Assessment of indirect tensile stress and tensile–strength ratio and creep compliance in HMA mixes with micro-silica and PMB
  95. Density functional theory to study stopping power of proton in water, lung, bladder, and intestine
  96. A review of single flow, flow boiling, and coating microchannel studies
  97. Effect of GFRP bar length on the flexural behavior of hybrid concrete beams strengthened with NSM bars
  98. Exploring the impact of parameters on flow boiling heat transfer in microchannels and coated microtubes: A comprehensive review
  99. Crumb rubber modification for enhanced rutting resistance in asphalt mixtures
  100. Special Issue: AESMT-6
  101. Design of a new sorting colors system based on PLC, TIA portal, and factory I/O programs
  102. Forecasting empirical formula for suspended sediment load prediction at upstream of Al-Kufa barrage, Kufa City, Iraq
  103. Optimization and characterization of sustainable geopolymer mortars based on palygorskite clay, water glass, and sodium hydroxide
  104. Sediment transport modelling upstream of Al Kufa Barrage
  105. Study of energy loss, range, and stopping time for proton in germanium and copper materials
  106. Effect of internal and external recycle ratios on the nutrient removal efficiency of anaerobic/anoxic/oxic (VIP) wastewater treatment plant
  107. Enhancing structural behaviour of polypropylene fibre concrete columns longitudinally reinforced with fibreglass bars
  108. Sustainable road paving: Enhancing concrete paver blocks with zeolite-enhanced cement
  109. Evaluation of the operational performance of Karbala waste water treatment plant under variable flow using GPS-X model
  110. Design and simulation of photonic crystal fiber for highly sensitive chemical sensing applications
  111. Optimization and design of a new column sequencing for crude oil distillation at Basrah refinery
  112. Inductive 3D numerical modelling of the tibia bone using MRI to examine von Mises stress and overall deformation
  113. An image encryption method based on modified elliptic curve Diffie-Hellman key exchange protocol and Hill Cipher
  114. Experimental investigation of generating superheated steam using a parabolic dish with a cylindrical cavity receiver: A case study
  115. Effect of surface roughness on the interface behavior of clayey soils
  116. Investigated of the optical properties for SiO2 by using Lorentz model
  117. Measurements of induced vibrations due to steel pipe pile driving in Al-Fao soil: Effect of partial end closure
  118. Experimental and numerical studies of ballistic resistance of hybrid sandwich composite body armor
  119. Evaluation of clay layer presence on shallow foundation settlement in dry sand under an earthquake
  120. Optimal design of mechanical performances of asphalt mixtures comprising nano-clay additives
  121. Advancing seismic performance: Isolators, TMDs, and multi-level strategies in reinforced concrete buildings
  122. Predicted evaporation in Basrah using artificial neural networks
  123. Energy management system for a small town to enhance quality of life
  124. Numerical study on entropy minimization in pipes with helical airfoil and CuO nanoparticle integration
  125. Equations and methodologies of inlet drainage system discharge coefficients: A review
  126. Thermal buckling analysis for hybrid and composite laminated plate by using new displacement function
  127. Investigation into the mechanical and thermal properties of lightweight mortar using commercial beads or recycled expanded polystyrene
  128. Experimental and theoretical analysis of single-jet column and concrete column using double-jet grouting technique applied at Al-Rashdia site
  129. The impact of incorporating waste materials on the mechanical and physical characteristics of tile adhesive materials
  130. Seismic resilience: Innovations in structural engineering for earthquake-prone areas
  131. Automatic human identification using fingerprint images based on Gabor filter and SIFT features fusion
  132. Performance of GRKM-method for solving classes of ordinary and partial differential equations of sixth-orders
  133. Visible light-boosted photodegradation activity of Ag–AgVO3/Zn0.5Mn0.5Fe2O4 supported heterojunctions for effective degradation of organic contaminates
  134. Production of sustainable concrete with treated cement kiln dust and iron slag waste aggregate
  135. Key effects on the structural behavior of fiber-reinforced lightweight concrete-ribbed slabs: A review
  136. A comparative analysis of the energy dissipation efficiency of various piano key weir types
  137. Special Issue: Transport 2022 - Part II
  138. Variability in road surface temperature in urban road network – A case study making use of mobile measurements
  139. Special Issue: BCEE5-2023
  140. Evaluation of reclaimed asphalt mixtures rejuvenated with waste engine oil to resist rutting deformation
  141. Assessment of potential resistance to moisture damage and fatigue cracks of asphalt mixture modified with ground granulated blast furnace slag
  142. Investigating seismic response in adjacent structures: A study on the impact of buildings’ orientation and distance considering soil–structure interaction
  143. Improvement of porosity of mortar using polyethylene glycol pre-polymer-impregnated mortar
  144. Three-dimensional analysis of steel beam-column bolted connections
  145. Assessment of agricultural drought in Iraq employing Landsat and MODIS imagery
  146. Performance evaluation of grouted porous asphalt concrete
  147. Optimization of local modified metakaolin-based geopolymer concrete by Taguchi method
  148. Effect of waste tire products on some characteristics of roller-compacted concrete
  149. Studying the lateral displacement of retaining wall supporting sandy soil under dynamic loads
  150. Seismic performance evaluation of concrete buttress dram (Dynamic linear analysis)
  151. Behavior of soil reinforced with micropiles
  152. Possibility of production high strength lightweight concrete containing organic waste aggregate and recycled steel fibers
  153. An investigation of self-sensing and mechanical properties of smart engineered cementitious composites reinforced with functional materials
  154. Forecasting changes in precipitation and temperatures of a regional watershed in Northern Iraq using LARS-WG model
  155. Experimental investigation of dynamic soil properties for modeling energy-absorbing layers
  156. Numerical investigation of the effect of longitudinal steel reinforcement ratio on the ductility of concrete beams
  157. An experimental study on the tensile properties of reinforced asphalt pavement
  158. Self-sensing behavior of hot asphalt mixture with steel fiber-based additive
  159. Behavior of ultra-high-performance concrete deep beams reinforced by basalt fibers
  160. Optimizing asphalt binder performance with various PET types
  161. Investigation of the hydraulic characteristics and homogeneity of the microstructure of the air voids in the sustainable rigid pavement
  162. Enhanced biogas production from municipal solid waste via digestion with cow manure: A case study
  163. Special Issue: AESMT-7 - Part I
  164. Preparation and investigation of cobalt nanoparticles by laser ablation: Structure, linear, and nonlinear optical properties
  165. Seismic analysis of RC building with plan irregularity in Baghdad/Iraq to obtain the optimal behavior
  166. The effect of urban environment on large-scale path loss model’s main parameters for mmWave 5G mobile network in Iraq
  167. Formatting a questionnaire for the quality control of river bank roads
  168. Vibration suppression of smart composite beam using model predictive controller
  169. Machine learning-based compressive strength estimation in nanomaterial-modified lightweight concrete
  170. In-depth analysis of critical factors affecting Iraqi construction projects performance
  171. Behavior of container berth structure under the influence of environmental and operational loads
  172. Energy absorption and impact response of ballistic resistance laminate
  173. Effect of water-absorbent polymer balls in internal curing on punching shear behavior of bubble slabs
  174. Effect of surface roughness on interface shear strength parameters of sandy soils
  175. Evaluating the interaction for embedded H-steel section in normal concrete under monotonic and repeated loads
  176. Estimation of the settlement of pile head using ANN and multivariate linear regression based on the results of load transfer method
  177. Enhancing communication: Deep learning for Arabic sign language translation
  178. A review of recent studies of both heat pipe and evaporative cooling in passive heat recovery
  179. Effect of nano-silica on the mechanical properties of LWC
  180. An experimental study of some mechanical properties and absorption for polymer-modified cement mortar modified with superplasticizer
  181. Digital beamforming enhancement with LSTM-based deep learning for millimeter wave transmission
  182. Developing an efficient planning process for heritage buildings maintenance in Iraq
  183. Design and optimization of two-stage controller for three-phase multi-converter/multi-machine electric vehicle
  184. Evaluation of microstructure and mechanical properties of Al1050/Al2O3/Gr composite processed by forming operation ECAP
  185. Calculations of mass stopping power and range of protons in organic compounds (CH3OH, CH2O, and CO2) at energy range of 0.01–1,000 MeV
  186. Investigation of in vitro behavior of composite coating hydroxyapatite-nano silver on 316L stainless steel substrate by electrophoretic technic for biomedical tools
  187. A review: Enhancing tribological properties of journal bearings composite materials
  188. Improvements in the randomness and security of digital currency using the photon sponge hash function through Maiorana–McFarland S-box replacement
  189. Design a new scheme for image security using a deep learning technique of hierarchical parameters
  190. Special Issue: ICES 2023
  191. Comparative geotechnical analysis for ultimate bearing capacity of precast concrete piles using cone resistance measurements
  192. Visualizing sustainable rainwater harvesting: A case study of Karbala Province
  193. Geogrid reinforcement for improving bearing capacity and stability of square foundations
  194. Evaluation of the effluent concentrations of Karbala wastewater treatment plant using reliability analysis
  195. Adsorbent made with inexpensive, local resources
  196. Effect of drain pipes on seepage and slope stability through a zoned earth dam
  197. Sediment accumulation in an 8 inch sewer pipe for a sample of various particles obtained from the streets of Karbala city, Iraq
  198. Special Issue: IETAS 2024 - Part I
  199. Analyzing the impact of transfer learning on explanation accuracy in deep learning-based ECG recognition systems
  200. Effect of scale factor on the dynamic response of frame foundations
  201. Improving multi-object detection and tracking with deep learning, DeepSORT, and frame cancellation techniques
  202. The impact of using prestressed CFRP bars on the development of flexural strength
  203. Assessment of surface hardness and impact strength of denture base resins reinforced with silver–titanium dioxide and silver–zirconium dioxide nanoparticles: In vitro study
  204. A data augmentation approach to enhance breast cancer detection using generative adversarial and artificial neural networks
  205. Modification of the 5D Lorenz chaotic map with fuzzy numbers for video encryption in cloud computing
  206. Special Issue: 51st KKBN - Part I
  207. Evaluation of static bending caused damage of glass-fiber composite structure using terahertz inspection
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Heruntergeladen am 7.9.2025 von https://www.degruyterbrill.com/document/doi/10.1515/eng-2022-0589/html?lang=de
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