High Seismic Risk Zones Research Articles

Can we develop a more targeted approach to mitigating seismic risk?

The recent high death tolls caused by large earthquakes are a further indication that earthquakes remain one of the most destructive natural hazards in the world and can seriously threaten the achievement of disaster reduction goals. To effectively reduce the existing seismic risk, the limited available mitigation resources should be allocated to areas with the most severe potential risk. However, identifying localized concentrations of risk requires detailed studies. Here, we propose a strategy to delineate regional high seismic risk zone at a fine resolution and with high confidence. We demonstrate this strategy by using the seismic hazard and loss estimation results for earthquake scenarios with a magnitude of Mw 7.5 for the Jiaocheng fault of the Shanxi Rift System, China. Our analyses reveal that the delineated zone accounts for only ~7% of the regional land area but for ~85% of the total financial loss. We recommend prioritizing seismic risk mitigation measures in such high-risk zones, especially for densely populated cities in seismically active areas, to better meet the disaster risk reduction targets in the Sendai Framework.

Multi-model seismic susceptibility assessment of the 1950 great Assam earthquake in the Eastern Himalayan front

The seismic susceptibility and mitigation management is paramount concern in tectonically active area like Northeastern India. This area has been devastated innumerably during the 1950 Assam great earthquake. The present study area falls in the foreland basin (Brahmaputra Valley) of Eastern Himalaya. This region is seismically vulnerable due to the tectonic complexity caused by the convergence of the Eurasian, Indian, and Burmese plates. In such, an area optimal disaster management and preparedness is necessary to define the non-linear character of seismic susceptibility, where population and unscientific urbanization have increased manifold. Therefore, for the present study, various multi-criteria decision making (MCDM) methods such as analytical hierarchy process (AHP), fuzzy-AHP (FAHP), and maximum entropy technique (MaxEnt) have been used for determining the seismic susceptibility, by assigning weightage to nine controlling factors such as: predominant frequency (f0), geology (G), vulnerability index (K), peak amplification (A0), liquefaction potential (LP), groundwater condition (WT), shear wave velocity (Vs30), peak ground acceleration (PGA), and land use/land cover (LU). The MaxEnt model exhibits the highest accuracy (87.5%) when the performance of the models was compared using the receiver operating characteristic curve (ROC) and area under the curve (AUC) value. Further, overlay analysis of best seismic susceptibility model using MaxEnt and PGV-based Japan Meteorological Agency (JMA) intensity shows that 40% the study area is in the very high and high seismic risk zone. In tectonically active areas, this kind of integration work is essential to improves the mitigation strategy and aids urban planners in designing earthquake-resistant buildings.

Seismic performance assessment of post-tensioned CLT shear wall buildings with buckling-restrained axial fuses

Post-tensioned cross-laminated timber (PT-CLT) walls have been demonstrated to be a low-damage seismic force-resisting system (SFRS) due to their self-centering capability. However, there is still a need to examine the seismic performance of such SFRS in high-seismic risk zones. This study evaluates the seismic performance of 6-, 9-, and 12-storey PT-CLT shear wall buildings in Vancouver, Canada, equipped with buckling-restrained axial fuses. The prototype buildings were designed using the displacement-based design method, and the assessment considered the most recent seismic hazard model provided in the 2020 National Building Code of Canada. To conduct nonlinear response history analysis (NLRHA) and incremental dynamic analysis (IDA), numerical models were developed in OpenSeesPy and calibrated based on component- and system-level experimental tests. The NLRHA and IDA results demonstrate that all the studied buildings have adequate collapse margin ratios, with less than a 10% chance of collapsing at the maximum considered earthquakes.

ON RADON ACTIVITY OF TECTONIC FAULTS IN THE AREA OF SITING THE SINOP NPP IN THE REPUBLIC OF TŰRKIYE

Problem statement. The paper provides an additional expanded justification for applying an innovative methodology in the area of the future Sinop NPP, planned to be deployed in the Republic of Tűrkiye, to identify the activity rate of tectonic faults in soil foundation based on comprehensive radon measurements using the PSACEA universal estimation scale. The purpose of the article. Current radon activity assessment of existing tectonic faults in Earth’s crust based on archival measurements of soil radon carried out earlier in Sinop Province. Conclusions and results. Current analysis of radon measurement results obtained previously by the track method made it possible to further assess the radon activity rate of tectonic faults existing in the area of the future nuclear power plant. The proposed methodology to assess radon activity of tectonic faults in Earth’s crust involves increasing safety during the construction and operation of the future nuclear power plant. The regulation on using this methodology as part of the subsurface monitoring at the Sinop NPP can be enshrined in job descriptions. This methodology can also be used as part of the seismic monitoring of other sites at the nuclear power plant, especially those located in high seismic risk zones.

An innovative shear links as dampers compound of shear plates and round HSS sections

Though concentrically braced frames pertain to high elastic stiffness and strength, their low ductility has been introduced as a no-desirable system in the high seismic risk zone. Utilizing passive energy dampers as a capable and economical idea, the shortcoming can be solved. Experimental and numerical studies on the pipe dampers confirmed their satiable performance in the case of ductility and dissipating energy capacity. But, it is suffered from low strength and stiffness. To overcome the shortcoming of these types of metallic dampers, in this paper, the strengthening of pipe damper with shear plates is proposed and investigated numerically and parametrically. Subsequently, the required equations (in good agreement with finite element results) were presented to design and predict the behavior o the damper. Results indicated that by reduction of the length to the height of the damper, the strength and stiffness are improved. Also, the ratio of the strength of the flanges to the strength of the web affects the behavior of the damper, and increasing this ratio reduces the stiffness and ultimate strength. Therefore, it is suggested that this ratio should be greater than 1.5.

Resonant column and cyclic torsional shear tests on Sutlej river sand subjected to the seismicity of Himalayan and Shivalik hill ranges: A case study

The study of site-specific dynamic properties of soil holds vital importance in many geotechnical engineering problems for the region holding high active seismicity. The Sutlej River basin, a valley and high-risk seismic zone in the north-eastern part of the Punjab state, has been considered for the study. The site-specific shear modulus reduction curves and material damping ratio curves for a range of shear strain amplitudes have been developed under varying experimental conditions of confining pressure, relative density, and loading frequency using the resonant column (RC) tests and cyclic torsional shear (CTS) tests. The study addresses the usage of two testing approaches, i.e., resonant column test (RC) and cyclic torsional shear test (CTS), for the estimation of shear modulus and damping ratio values at varying shear strain amplitudes. The regression analysis has been performed for the two testing techniques viz. RC and CTS to study the sensitivity of shear modulus values and material damping ratio values towards varying experimental conditions. The shear modulus and damping ratio values determined from cyclic torsional shear tests were observed to have great dependency on the frequency of loading. The knowledge of site-specific dynamic properties will support practical interpretation for the geotechnical engineering problems in the region.

Comparative study of the cost and behavior of RC special moment frame buildings with drop and hidden beams subjected to seismic loads

This study presents a comparative analysis between two structural design ideas in the Ecuadorian construction market: hidden vs. drop beams. Due to its location in a high seismic zone, structural design considerations in Ecuador must be made with care. Therefore, to offer improved strength to seismic forces, special moment frames are the most common structural system used. However, hidden beams are popular in low story buildings because of a notion of a cheaper system, despite evidence of collapse during earthquake events. In this study we look at special moment frames using hidden type and drop type beams, in terms of cost, structural, and seismic performance. A total of 32 structural models are analyzed, out of which 16 are models of buildings containing hidden beams and another 16 are drop beams. Linear and nonlinear static analysis, nonlinear local analysis, and moment curvature analysis of the modeled structures are performed to compare their seismic behavior. The structural design is carried out based on linear static analysis to obtain the total cost of all models. Additionally, a nonlinear static pushover analysis was conducted to assess roof displacement. The evidence shows that when using hidden beams, roof displacement is 20%–55% higher than when using drop beams, despite the nearly negligible differences in terms of cost. The evidence also shows that structures with drop beams, have a 22%–28% higher nominal flexural moment than structures with hidden beams, while achieving a 27%–31% higher curvature ductility. This research shows evidence on how structures with drop beams have a better behavior in high seismic risk zones when compared to structures with hidden beams, whose use although allowed, should be limited.

Performance evaluation of eco-friendly scrap tyre base isolation technology in distinct construction quality RC framed buildings located in seismic risk zone

The present investigation interprets the seismic and cost performance of scrap tyre rubber pad (STRP) bearings obtained from used automobile tyres to be installed in a developing country of a high seismic risk zone. As a consequence, Meghalaya, a state from India is selected for the research. The buildings vary in its construction quality such as poor, moderate and good construction and varying in storey heights such as three and five stories. Nonlinear analysis and cost-analysis of the buildings with and without STRP bearings are performed. The nonlinear modal time history analysis/fast nonlinear analysis is performed using SAP 2000 software and SeismoMatch software to check for convergence of the selected accelerograms with target spectrum. The dynamic response such as base shear, acceleration, storey drift and displacement are discussed and compared. The study exemplifies that the base shear reduction is superior in good construction type buildings compared to poor construction type. Moderate construction type buildings report good acceleration response, storey drift and displacement response compared to poor and good construction type. Substantially, it is reported that there is a significant reduction in cost with the implementation of STRP bearings of about 12% to 25% which is a promising one.

Effects of near‐fault acceleration and non‐acceleration pulses on pounding between in‐plan irregular fixed‐base and base‐isolated buildings

Concave surface sliders (CSSs) are considered as an effective solution for retrofitting adjacent buildings irregular in plan that could undergo significant seismic pounding due to torsional displacements. This is because during the sliding phase there is coincidence between the projection of the gravity mass centre of the superstructure and the stiffness centre of the CSSs. However, unexpected torsional pounding, with amplification in a near-fault site, may be induced by variability of friction force and lateral stiffness of the CSSs, depending on the axial load and friction coefficient changes during an earthquake. In this work, structural pounding between fixed-base and base-isolated reinforced concrete (RC) L-shaped buildings, placed adjacent to form T- and C-shaped plans, is investigated. A simulated design of the original fixed-base framed structures is preliminarily carried out in accordance to a former Italian code, for a medium-risk seismic zone and a typical subsoil class. Then, seismic retrofitting with CSSs is carried out, to attain performance levels imposed by the current Italian code in a high-risk seismic zone and for moderately-soft subsoil. A computer code for the pounding analysis between fixed-base and base-isolated test structures is developed, in order to compare effects of nonlinear models of the CSSs that consider constant and variable axial load combined with friction coefficient at breakaway and stick–slip and as function of the sliding velocity, axial pressure and rising temperature at the sliding interface. Attention is focused on the pulse-type nature of near-fault earthquakes generally observed in the velocity time histories but largely overlooked in the acceleration ones. To this end, automated classification algorithms using wavelet analysis are adopted to compile three datasets of seismic input distinguishing between no-pulse and velocity-pulse, the latter further categorised into non-acceleration and acceleration pulses and rotated along the direction most likely to contain strong pulses.

Método de reforçamento estrutural para avaliação do encamisamento em pilares com amplificação de momentos sob cargas sísmicas

Abstract Different reasons can make certain structures need reinforcement to achieve specific levels of safety and performance. The occurrence of events of significant magnitudes, such as earthquakes, are examples of this. Retrofitting vulnerable structures becomes a practice to mitigate the destructive effects of earthquakes, and the RC Jacketing becomes an alternative. The present work studies this type of reinforcement, proposing and applying an assessment methodology under vulnerable construction built in a high seismic risk zone. The diagnostic of the current situation was determined, and the structural suitability was evaluated using RC Jacketing. With the computational software S-Model, created in this research, the effectiveness of the proposed reinforcement was verified, based on the results of the analysis carried out with commercial software. The preload was considered, and the strength of the reinforced column section was verified against all load combinations. The S-Model program was able to verify the non-simultaneous occurrence of the amplification of moments with the most critical loading. Both conditions demand more significant stresses on the element, and therefore the calculation of the steel areas of the column may be underestimated if they are not considered.

Behaviour and Strengthening Methods of Tall Slender Columns in Earthquake Conditions

Reinforced concrete buildings are normally designed and constructed with well-defined vertical column supports which are able to withstand both vertical and lateral loadings. In the case of high columns there is a risk of instability due to its slenderness caused by the higher apex ratio (measured by its height in relation to the width). This is compounded by having such buildings located at medium to high seismic risk zones, where lateral dynamic loadings can occur. This research paper focused on how such slender reinforced concrete columns will behave under earthquake loading conditions, and highlights some innovative ways to strengthen the column capacity to withstand both vertical and lateral loadings. Besides the conventional ways to provide diagonal or lateral bracings, the use of glass fibre reinforced polymer (GFRP) as an alternative material for retrofitting tall slender reinforced concrete columns are presented here. The new method includes spraying of the GFRP onto the external surfaces of the columns and also incorporate the GFRP bars as additional reinforcement into the concrete columns. Both methods proved to improve the durability and strengthen the tall reinforced concrete column. This study shows the ability of the new method of amelioration of the slender reinforced concrete columns to increase their stability during seismic activity.

Effect of different RC slab widths on the behavior of reinforced concrete column and steel beam-slab subassemblies

In this paper, a total of three reinforced concrete column-steel beam (RCS) subassemblies with different RC slab widths following the strong column-weak beam criterion were tested under the reversed cyclic to investigate the influence of the RC slab on the load transfer mechanism and failure feature of composite connections. With appropriate joint detail, the tested specimens fully developed a desirable beam plastic hinge mechanism with stable and ductile hysteretic response. It was found that the effect of the composite beam-slab sections constrained the core concrete in the connection region was able to obviously improve the seismic performance of composite connections. Additionally, results from this research presented that the RC slabs made a limited contribution to the strength and stiffness of the connections beyond a certain limiting value for the RCS composite moment resisting frame. By analyzing the mechanic mechanism of reinforced concrete column and steel beam-slab connection, it was indicated that effective flange width of the composite beam-slab sections has a significant effect on the capacity of beam moment and equivalent elastic moment of inertia values. Based on the test results, some suggestions are presented for the design of the RCS frame systems, which demonstrates a viable alternative structures in high seismic risk zones.

Base-isolation of a hospital pavilion against in-plane-out-of-plane seismic collapse of masonry infills

The in-plane (IP) and out-of-plane (OOP) seismic collapse of masonry infills (MIs) may induce devastating economic and social consequences for public buildings such as hospitals in the aftermath of an earthquake. Yet no attention has been paid in the literature to base-isolation as a retrofitting technique for improving the IP and OOP response of these nonstructural components. To full this gap, a medical centre with a five-storey r.c. framed structure is first designed as fixed-base in a medium-risk zone, in compliance with a former Italian code. Four infill aspect ratios are examined, combining bays of different lengths with exterior and interior configurations of MIs in the perimeter frames. Four structural models of the hospital are considered: i.e. two bare structures with nonstructural MIs, fulfilling provisions of the former and current Italian codes for limiting nonstructural damage; two infilled structures, with the above configurations of structural MIs, applying only provisions of the former Italian code. To achieve full operational capacity in a high-risk seismic zone, these structures are retrofitted with base-isolation systems of high-damping-rubber bearings. To assess the integrity of the MIs a five-element macro-model predicts their IP and OOP nonlinear force–displacement laws and describes the effects of simultaneous or prior in-plane (IP) damage on the OOP behaviour. OOP drift- and acceleration-sensitivity of MIs are investigated through nonlinear dynamic analyses of the fixed-base and base-isolated hospitals subjected to far-fault and near-fault earthquakes corresponding to the life-safety limit state provided by current Italian code for strategic facilities. High levels of vulnerability and early IP and OOP collapse of MIs are obtained for all design procedures of the fixed-base structures, while a different distribution of the IP and OOP damage of MIs but no collapse in presence of a base-isolation system is observed depending on the formulation adopted for their nonlinear behaviour.

Seismic resilience evaluation of base-isolated RC buildings using a loss-recovery approach

Seismic isolation systems, especially friction pendulum bearings (FPBs), are used as ideal seismic protection strategies in performance-based design. Furthermore, FPBs can increase the functionality of buildings by minimizing interruption of use of the facility (e.g., operational performance level) and reducing seismic demands on the structural and non-structural elements. The primary objective of this paper is to investigate the seismic resilience of reinforced concrete (RC) buildings, especially essential buildings in compliance with a loss-recovery approach. To this end, an analytical examination is conducted concerning a six-story RC building, which was mainly designed under the Uniform Building Code (UBC in International Conference of Building Officials, Whittier, CA, 1997) for a high-risk seismic zone. The incremental dynamic analyses of the fixed-base and base-isolated structures subjected to a set of near and far-fault ground motions are carried out for getting seismic fragility and functionality curves as well as the resilience of structures using a loss-recovery approach. The proposed methodology is employed to special buildings such as hospital buildings, with and without using the FPBs considering different seismic hazard scenarios that could occur within the investigated region. At the end of the paper, a parametric study is conducted by changing the building and pendulum parameters. The benefit of the suggested approach is found in terms of loss-recovery and seismic resilience that will be well recognized by the decision-maker for better planning to decrease seismic losses, rather than waiting for an earthquake and paying for it afterward.

Application of Direct Displacement Based Design of Reinforced Concrete Frames Subjected To Earthquake Loads

Numerous studies are reported in literature on performance evaluation and rehabilitation of building however, limited studies are reported on performance based design of new buildings. Displacement based design procedure is a new method which is not available in Indian building design codes. An effort has been done to investigate the Direct Displacement Based Design (DDBD) for four, eight and twelve story regular RC frame buildings proposed by Priestley et al, using Indian code Response Spectrum for Zone V which is considered as a very high intensity seismic risk zone for life safety and collapse prevention performance levels. Nonlinear time history analysis is carried out for available ground motion and compared with the performance levels (in terms of drift, displacement). Observations show that design displacement reduction factor should be different for life safety and collapse prevention levels. The effective damping increases as the height of the building increases and is higher for collapse prevention.

Effects of Fire Duration on the Seismic Retrofitting With Hysteretic Damped Braces of r.c. School Buildings

School buildings are susceptible to high incidents of fire because of carelessness, faulty electrical installation and arson, raising the attention on their seismic retrofitting after fire exposure. Hot and residual mechanical properties of a reinforced concrete (r.c.) structure exposed to fire depend on duration of the heating and cooling phases. As a consequence, seismic retrofitting of a fire-damaged framed structure may not be effective when the peak temperature during a fire is considered. For a successful retrofit, ultimate capacity resulting from residual properties after cooling needs to be taken into account. To this end, the state secondary school Collina-Castello of Bisignano (Italy), a three-storey r.c. framed structure designed in a medium-risk seismic region to comply with a former Italian seismic code, is considered as test structure. Thermal analysis of r.c. frame members is preliminarily carried out for two fire scenarios, on the assumption that the fire compartment is confined to the ground (i.e. F0) and first (i.e. F1) levels. Moreover, four fire-damage cases are examined, considering only the heating phase, at 45 minutes of fire resistance, and the overall fire cycle, for fast, medium and slow phases of cooling. Afterwards, the school is supposed to be retrofitted with hysteretic damped braces (HYDBs), in order to achieve the performance levels imposed by current Italian code in a high-risk seismic zone. Nonlinear static and dynamic analyses of the unbraced and damped braced structures are carried out, with reference to the degradation of r.c. frame members for different fire durations in the design procedure of the HYDBs.

Foundation Design and Construction Challenges with Marsh Deposits in a High Seismic Risk Zone

Driven piles are ideal for supporting structures over very soft ground, especially in high seismic risk zones. Challenges include achieving sufficient vertical and lateral load capacities within the constraints of pile spacing and geologic conditions. Through a unique case study, the authors will describe the process of site exploration, foundation selection, pile design, and installation of over 3,000 concrete piles in a small 4.5-acre (1.8 hectare) site (average of one pile per 65 square feet). A state-of-the-art, $180 million plant for biosolids processing, biogas management and energy recovery was sited in marshland next to an existing sewage treatment plant. The new construction included a 70-foot (21 m) tall building and three closely spaced, 90-foot (27 m) high, 65-foot (20 m) diameter, egg-shaped steel digester tanks. The site, classified as class “F”, was underlain by up to 45 feet (14 m) of highly compressible peat and organic clays, below which was a dense sand and gravel layer. The groundwater was very shallow and site-specific seismic hazard analyses were required. Particularly challenging was achieving the needed lateral resistance to seismic loads in the very weak clay and peat deposits. The project was instructive of the importance of adequate characterization of geologic conditions even in small sites; the necessary iterative collaboration process between geotechnical and structural engineers; and the value of a well-designed indicator pile program. The test pile program allowed for refining (shortening) the design pile lengths for considerable cost savings and reduced installation time. Of interest to the reader will be the surprising depth to refusal for some areas of the site, despite the test pile program.

A simplified retrofitting method based on seismic damage of a SDOF system equivalent to a damped braced building

A new Displacement-Based Design (DBD) procedure to proportion hysteretic damped braces (HYDBs) is proposed in order to take into account the effects of the seismic degradation of a structure that needs to be retrofitted. To this end, a hysteretic model based on plastic and damage mechanisms is adopted to describe the inelastic response of reinforced concrete (r.c.) frame members. Then, nonlinear seismic analysis of a single-degree-of-freedom system, equivalent to a multi-degree-of-freedom model of the structure, is used to generate the capacity boundary curve by means of the hysteretic model defined starting from the initial backbone curve. Two-, four- and eight-storey r.c. framed structures are designed for a medium-risk seismic zone of a former Italian code. These are then to be retrofitted by inserting HYDBs to attain performance levels imposed by current Italian code in a high-risk seismic zone. Different retrofitting solutions are compared, considering for each retrofitted structure: (i) variable damper ductility coupled with constant frame ductility; (ii) variable frame ductility coupled with constant damper ductility. The effects of different damage levels and different damage evolution laws are also investigated. Finally, pushover curves of the unbraced and damped braced structures are carried out, with and without considering degradation of the hysteretic response of r.c. frame members on the DBD procedure of the HYDBs.

Perencanaan Struktur Rangka Baja Beraturan Tahan Gempa Berdasarkan SNI 02-1726-2002 dan FEMA 450

Wilayah Indonesia mencakup daerah-daerah yang mempunyai tingkat resiko gempa yang tinggidiantara beberapa daerah gempa diseluruh dunia. Hampir setiap tahun terjadi bencana akibat gempabumi di berbagai tempat di Indonesia. Gempa yang terjadi dapat mengakibatkan kerusakan yangmenimbulkan korban jiwa serta dampaknya besar terhadap ekonomi dan pembangunan daerah diwilayah tersebut. Tujuan penelitian ini adalah melakukan perencanaan struktur gedung baja tahangempa berdasarkan peraturan SNI 02-1726-2002 dan FEMA 450, dan pembahasan meliputi penentuanukuran profil baja yang digunakan sebagai elemen struktur balok dan kolom, gaya geser dasar,peralihan, desain sambungan, dan perhitungan pondasi. Hasil desain balok dan kolom denganmenggunakan beban gempa berdasarkan SNI 02-1726-2002 dan FEMA 450 memberikan hasil yangsama untuk nilai rasio P/M. Nilai gaya geser nominal arah-x (Vx) mempunyai perbedaan sebesar0,08%, sedangkan nilai gaya geser nominal arah-y (Vy) mempunyai perbedaan sebesar 0,16%. Hal initerjadi karena hasil perhitungan nilai Fxi dan Fyi dengan kedua metode tersebut memberikan hasil yanghampir sama. Perbedaan nilai Vu pada balok sebesar 0,09%, dan Mu mempunyai selisih sebesar0,00%. Nilai Vu dan Mu pada kolom mempunyai hasil yang sama, perbedaan nilai Nu sebesar 0,18%.Pada reaksi tumpuan, memberikan hasil yang hampir sama, sehingga menghasilkan pondasi danpilecap yang sama. Pada desain sambungan, baut dan pelat mempunyai hasil yang sama, hal inidikarenakan perbedaan nilai Nu, Vu, dan Mu berdasarkan SNI 02-1726-2002 dan FEMA 450 sangatkecil. Secara umum, metode SNI 02-1726-2002 dan FEMA 450 memberikan perbedaan hasilperhitungan yang tidak signifikan.

The effect of composite-elastomer isolation system on the seismic response of liquid-storage tanks: Part I

A typical viable technique to decrease the seismic response of liquid storage tanks is to isolate them at the base. Base-isolation systems are an efficient and feasible solution to reduce the vulnerability of structures in high seismic risk zones. Nevertheless, when liquid storage tanks are under long-period shaking, the base-isolation systems could have different impacts. These kinds of earthquakes can damage the tanks readily. Hence, the seismic behaviour and vibration of cylindrical liquid storage tanks, subjected to earthquakes, is of paramount importance, and it is investigated in this paper. The Finite Element Method is used to evaluate seismic response in addition to the reduction of excessive liquid sloshing in the tank when subjected to the long-period ground motion. The non-linear stress-strain behaviour pertaining to polymers and rubbers is implemented while non-linear contact elements are employed to describe the 3-D surface-to-surface contact. Therefore, Nonlinear Procedures are used to investigate the fluid-structure interactions (FSI) between liquid and the tank wall while there is incompressible liquid. Part I, examines the effect of the flexibility of the isolation system and the tank aspect ratio (height to radius) on the tank wall radial displacements of the tank wall and the liquid sloshing heights. Maximum stress and base shear force for various aspect ratios and different base-isolators, which are subjected to three seismic conditions, will be discussed in Part II. It is shown that the composite-base isolator is much more effective than other isolators due to its high flexibility and strength combined. Moreover, the base isolators may decrease the maximum level pertaining to radial displacement.