SCA CONSTRUCTION CONCEPTS

INTRODUCTION

The occurrence of strong earthquakes (when and where) is a natural phenomenon that is extremely difficult to detect and that causes enormous losses throughout the earth. In the past 1 year alone, according to the records of the United States Geological Survey (USGS), earthquakes (and their after-effects, tsunamis) have caused 300 thousand casualties and 1000 trillion in material losses. Since earthquake engineering and prediction have not yet reached a final solution, the study of the engineering aspects of earthquake-resistant structures remains a relevant research object.

Over the past 10 years, the concept of earthquake-resistant design has shifted from a design concept based on structural strength or structural elements to a design concept based on limit states, called Performance-Based Design. The change in design philosophy in building standards/codes was first contained in the 1995 Structural Engineering Association of California (SEAOC) and Applied Technology Council (ATC) review. Then the new concept was documented in NEHRP 1997, FEMA 302 and UBC 1997. And, most recently in SEAOC Vision 2000.

This shifting trend is due to several reasons, namely:
1. In reaction to the structural failures of conventional design methods, especially strength-based design, in several major earthquakes (Reconnaissance Reports on the 1989 Loma Prieta earthquake, 1994 Northridge earthquake and 1995 Kobe earthquake). Traditional methods were deemed inaccurate in accommodating earthquake loads and their effects.
2. There is a need to control structural performance, which is primarily aimed at ensuring the stability of the structure’s seismic resistance during strong earthquakes.

This book presents the concept of formulating earthquake-resistant construction using the direct deformation method in an effort to control structural performance. Direct deformation is defined as an analysis procedure based on the estimation of lateral displacements expected to occur due to earthquake-induced ground shaking, where design force components are then determined based on the calculated deformations. The lateral deformation or displacement thus becomes the main design parameter associated with the overall structural response.

THIS BOOK PRESENTS…1. As a maximum effort in responding to failures that often occur due to Earthquakes, 2. Maximum effort in creating an Earthquake Resistant Structure analysis model to prevent serious Building Structure failures that can result in aspects of human life safety.

EARTHQUAKE ENGINEERING FOR CONSTRUCTION

Assoc. Professor Dr. Ir. Ayuddin., S.T., M.T., IPU., ASEAN Eng., ACPE., APEC Eng.
(Researcher and Analyst of Earthquake Resistant Structures )

The concentration in Structural Civil Engineering is a relatively interesting science that even encourages interest in conducting serious studies because it is related to the safety of human life. The main objective is to design or analyze a building construction that is resistant to earthquake loads. Buildings that are designed or analyzed according to earthquake-resistant procedures have an effect on the safety of human life considering that the effects of an earthquake in a region can hit a building until it collapses. Active earthquake zones that occur with peak ground acceleration (PGA) can reach 0.4g or even higher. On this basis, a building to be erected must be designed with sharp analysis to withstand excessive earthquake loads with minimal damage and avoid loss of life. High experience is required in the design of earthquake-resistant construction of various concrete, steel and timber structural systems, as well as non-structural elements and various building service systems.

One method of linking earthquake forecasts to the design and analysis of a building is through numerical modeling. Earthquake engineering is greatly enhanced by modeling the way in which certain types of structures will respond to seismic activity. Experience in using the latest versions of finite element analysis programs such as Etabs and SAP2000 is required in designing and modeling a structure. Structural damage can be significantly reduced through robust prediction of possible future earthquakes that could occur during the life of the structure and through accurate modeling of the nonlinear behavior of the structure under earthquake loading. Earthquake engineering has evolved from the use of a set of prescriptive provisions indirectly aimed at providing life safety to a performance-based approach. The performance-based approach has several advantages by offering a more effective way to design structural systems to achieve better performance objectives. It consistently considers the seismic hazard, structural response and structural damage so that a full probabilistic assessment of the expected performance of the structure can be made.