1.0.1 According to guideline putting prevention first in seismic work, in order to guarantee safety of the existing industrial construction under seismic action and make the construction not to be severely damaged under seismic intensity which is the same as that adopted for appraisal and strengthening of antiseismic performance and still may be continued in service after repair, this standard is formulated.
1.0.2 This standard is applicable to appraisal and strengthening of antiseismic performance of Intensity 7, Intensity 8 and Intensity 9 and that of existing industrial construction without antiseismic design.
1.0.3 Intensity for appraisal and strengthening of antiseismic performance should be adopted according to basic intensity of location area; for construction of special importance, where appraisal and strengthening of antiseismic performance must be carried out by improving 1 intensity, the appraisal and strengthening of the construction shall be reported according to national requirements for approval.
Notes: ① For important factories and mines, if conditions permit, appraisal and strengthening of antiseismic performance may be carried out according to microzonation or design response spectrum of approved seismic intensity.
② In region with basic intensity as Intensity 6, for industrial construction needs to be carried out with antiseismic fortification according to national special requirements, appraisal and strengthening of antiseismic performance may be carried out according to the requirements of Intensity 7 region in this standard.
1.0.4 Appraisal and strengthening of antiseismic performance shall be considered from overall situation of improving comprehensive antiseismic ability of factories and mines and shall meet the following requirements:
I Comprehensive analysis is carried out on feasibility and technical and economic rationality of overall strengthening scheme.
II Comprehensive analysis for site and subgrade influence on antiseismic performance of construction structure and reasonable strengthening are carried out.
III Comprehensive consideration is carried out for seismic safety of building group and interaction of every class adjacent building and construction and its damage consequence under earthquake is analyzed from whole production line; and then comprehensive treatment is carried out to relieve secondary disaster.
IV Construction requirements are strict to ensure the engineering quality and the acceptance is practically organized.
V Reasonable maintenance shall be carried out for the construction in service.
1.0.5 Appraisal and strengthening of antiseismic performance shall be carried out according to importance of construction and graded according to the following requirements:
I Class A buildings: in large factories (mines), constructions whose seismic damage will cause serious consequences to continuous production and personnel life, including power system construction in the whole factory (mine) and in specially important workshop, construction resulting in severe secondary disaster after being damaged in earthquake or construction with strong impact on first aid after earthquake, and emergency exits.
II Class B buildings: other constructions except Class A and Class C buildings.
III Class C buildings: constructions whose destruction will not cause casualty or relatively large economic losses or other secondary constructions.
1.0.6 Where appraisal and strengthening of antiseismic performance is to be carried out, relevant investigation, design and construction, original information, current state and potential hazard of construction in combination with earthquake damage experience of structure and subgrade of same class construction shall be surveyed in advance, and favorable factor and adverse factor of site and subsoil conditions for antiseismic fortification of construction shall be analyzed.
1.0.7 For current state of each class structure not meeting the following relevant requirements, treatment shall be carried out in combination with antiseismic strengthening.
I Steel structure:
1 Loaded member and rod piece (including brace) are free from shortage, visible bending, crack and hole or notch formed by cutting.
2 Loaded member, rod piece, their connection and joints are free from rust.
3 Anchor bolt is free from damage and rust and nut is free from looseness; for shear anchor bolt, its bolt rod is free from screw thread at cover plate of bracket. Foundation concrete is free from flaky crack and corrosion.
4 Supporting length of loaded member meets the requirements of non-seismic design.
5 Crossing point of the center line of column brace diagonal and the center line of column is not located at upper/lower column section of floor slab and column section above foundation.
II Reinforced concrete structure:
1 Loaded member and rod piece are free from shortage, obvious deformation and damage formed by cutting and punching.
2 Concrete of loaded member and rod piece is free from flaky crack, corrosion, burning loss, shedding, exposed reinforcement and crack exceeding limit of design requirements.
3 Supporting length of precast loaded member meets the requirements of non-seismic design.
4 Connections are free from rust.
5 Where infilled wall or column brace is set up, eccentricity from center of mass of structural unit to rigid center in not enlarged and sudden change of horizontal rigidity along height direction doesn't occur; linear rigidity of column is not enlarged or short column is not formed due to half height rigid wall.
III Brick structure:
1 Wall is free from hollowing, skewing and crisp alkali.
2 Junctions of load bearing wall and vertical and horizontal wall are free from cracks, have favorable bite raft, and free from hole (formed by excavating) apparently weakening antiseismic capability of the original structure.
3 Local size of each part meets the specified limit requirements of the current national standard "Standard for Seismic Appraisal of Buildings".
4 Brick beam is free from crack and deformation.
5 There are no wall crack caused by non-uniform settlement of subgrade and other visible defects affecting the wall quality.
1.0.8 For construction which may not be carried out with antiseismic checking and antiseismic strengthening specified in relevant chapters and sections of this standard shall meet the following requirements:
I The requirements of non-seismic design and construction acceptance specification are met.
