Steel Buildings in Europe

Part 7: Model Construction Specification 7 - 14 According to § 3.4(1) of EN 1991-1-7, the strategies for accidental design situations may be based on the Consequence Classes as set out in EN 1990. Thus, these Consequence Classes shall be specified in the contract documents. According to § 4.3.1(2) of EN 1991-1-7, the contract documents shall specify whether or not the equivalent static design forces due to vehicular impact on members supporting structures over or adjacent to roadways, F dx and F dy , act simultaneously. According to § 4.5.1.2 of EN 1991-1-7, if the building may be subject to impact from derailed railway traffic, the contract documents shall define whether it is a Class A or Class B structure. According to § 4.5.1.2(1) of EN 1991-1-7, frontal and lateral dynamic design forces due to impact from river and canal traffic, as well as the height of application of the impact force and the impact area shall be specified in the contract documents. 4.7 Seismic actions EN 1998-1 applies to the design and construction of buildings and civil engineering works in seismic regions. Its purpose is to ensure that in the event of earthquakes:  Human lives are protected  Damage is limited  Structures important for civil protection remain operational (special structures such as nuclear power plants, offshore structures and large dams, are beyond the scope of EN 1998-1). One fundamental issue in EN 1998-1 is the definition of the seismic action. Given the wide difference of seismic hazard and seismo-genetic characteristics in the various member countries, the seismic action is herein defined in general terms. The definition allows various Nationally Determined Parameters which shall be confirmed or modified in the National Annexes. National choice is allowed through clauses listed in the Foreword to EN 1998-1. Additional contract document requirements According to § 2.1(2) and (3) of EN 1998-1, target reliabilities for the no-collapse requirement and for the damage limitation requirement are established by the National Authorities for different types of buildings on the basis of the consequences of failure. Contract documents shall specify the Importance Class of the individual project (see 4.2.5 of EN 1998-1). Depending on the Importance Class of the structure and the particular conditions of the project, contract documents shall specify whether or not ground investigations and/or geological studies shall be performed to identify the ground type (A, B, C, D, E, S1 or S2), according to Table 3.1 of EN 1998-1.