1. Safety inspection and assessment of existing building structures
Existing buildings are constructed and put into use, these buildings are generally completed by the acceptance of qualified. It is generally necessary to evaluate the safety of the structure by reviewing the layout and loading of the structure, testing the material properties, detecting the damage of the cracks, measuring the settlement and deformation, and checking and analyzing the structure. Necessary reinforcement recommendations. When the following conditions, the need for the safety of existing building structures to be detected and assessed, and various situations of structural safety assessment has focused on assessment:
(1) housing due to investigation, design, construction, use and other reasons, cracks or tilt deformation occurs. In addition to assessing structural safety and proposing treatment suggestions, these projects usually need to analyze the cause of damage, analyze which part of survey, design, construction and use will cause the existing damage and provide the basis for the responsibility identification. Residential quality control and arbitration identification are mostly of such projects.
(2) Housing due to material, environmental and other reasons, the use of life in the design of the impact of security or the use of degradation, signs of aging. The concrete structure, the material factor may have the concrete aggregate contains the MgO and so on the active ingredient, the cement alkali content is excessively high, the cement stability bad, mixes the water to contain the excess and so on, the environmental factor may have the chemical substance, the freezing and thawing cycle, These factors may cause deterioration of concrete, steel corrosion, chemical corrosion, alkali-aggregate reaction, freeze-thaw damage, and aging. The main aging signs of steel structure are steel corrosion, and the main signs of aging are brick wall weathering, wood The main signs of aging of the structure are worm erosion and decay. This kind of structural safety testing and evaluation, generally need to carry out material and environmental analysis, to find the main cause of deterioration or aging, to predict the degree of deterioration or aging, and to propose effective measures to deal with recommendations.
(3) housing due to the impact of adjacent works, cracks or tilt deformation occurs. This kind of structural safety testing and evaluation, the focus is to distinguish between housing cracks or tilt deformation caused by housing itself or adjacent to the impact caused by the construction of the pit, assess the safety of the structure and put forward reasonable measures to deal with recommendations. As many of these projects commissioned after the injury or deformation occurred, the parties may have been in conflict, it also has more court commissioned by the arbitration appraisal project.
(4) the use of housing or local structural changes, the impact on structural safety. The use of the process of housing may occur with the use of functional changes, such as plant to office building, office building of the mall, may also need to open some openings, partial floor openings, local pumping beam column and other local structural changes, these factors on the structure Safety, impact assessment, assessment of the safety of the use of new functional and structural arrangement of structural components and structural safety assessment of structural safety. When the functional and structural changes are large, the need for seismic performance evaluation.
(5) housing over the design of service life to continue service. In general, when the house more than the design life to continue service, housing will appear different degrees of signs of aging, its structural function of the degradation of varying degrees, the need for comprehensive testing and evaluation, in addition to routine testing and evaluation content, the focus lies in the prediction Structure life, set the next target life and propose recommendations for durability. When the existing buildings in accordance with the relevant standards were rated as dilapidated buildings, the test report shall be sent to the Shanghai Housing Inspection Center to organize technical review.
2. Quality inspection and assessment of existing housing projects
Due to various reasons, design, construction and other information is incomplete, the completion of the housing can not handle the completion of acceptance procedures, or although the information is complete, but without the completion of acceptance procedures that are delivered. Detection and evaluation of such housing is generally for the completion of the completion of the procedures for acceptance or property rights certificates purposes. In addition to the contents of routine safety testing and evaluation, the focus is to detect the construction quality of housing projects, including component cross-section deviation, verticality, flatness, surface defects, steel and other hidden projects, material strength; , Structural drawings.
3. Housing reconstruction seismic evaluation
In the process of house construction, when the construction is stopped or during the process of construction, it is necessary to add the layer, intercalation, expansion, or a wide range of structural system or use the functional change, etc., the original structure of seismic identification, The original structural system and the structure are identified, the structural seismic calculation is carried out according to the rebuilding structure, the seismic performance of the retrofit structure and the feasibility of the retrofit scheme are synthetically evaluated. If necessary, the reconstruction scheme optimization measures and the original structural aseismic reinforcement Measures proposed. Earthquake-proof housing reconstruction should generally be based on the existing seismic design standards.
4. Excellent historical building detection and evaluation
Shanghai is a national historical city, there are a large number of outstanding historical buildings. According to the Regulations on the Protection of Historical and Cultural Areas and Excellent Historic Buildings in Shanghai, the problems that affect the safety or normal use during the use of excellent historical buildings, the use of functional or local structural changes, the continued use of the design life, Before the overhaul, all must carry on the comprehensive examination appraisal. In accordance with the "Shanghai excellent modern building quality inspection and management of Interim Provisions" and the Shanghai "housing quality testing procedures" DGJ08-79-2008, excellent historical building inspection and evaluation, in addition to conventional safety testing content, the need for history Structural investigation, architectural style analysis, inspection of key protection sites, surveying of architectural and structural drawings, equipment operation and completion degree, seismic performance evaluation of structures according to seismic evaluation criteria. The inspection program and report of the excellent historical building inspection and evaluation project shall be submitted to the Municipal Housing Inspection Center for technical examination. I station has completed a number of outstanding historical building inspection and evaluation projects, representative projects along the Bund to protect buildings and so on.
5. Housing damage trend detection, monitoring and evaluation
During the construction of adjacent projects, the damage trend of the existing buildings within the scope of construction influence shall be detected, monitored and evaluated. Complete housing damage trend detection, monitoring and evaluation The project is divided into three phases: Before the construction of adjacent buildings, the status quo of the surrounding houses are detected, including structural system investigation, complete damage detection, settlement deformation measurement, settlement and cracks Monitoring points, put forward the preliminary test report, if necessary, analyze the impact of the adjacent construction on the surrounding houses, put forward settlement and crack monitoring alarm value, put forward the construction plan to improve the views and monitoring requirements. During the construction of adjacent projects, the monitoring points for settlement and cracks shall be regularly monitored, and the monitoring reports and alarm and reinforcement measures shall be put forward if necessary. After the completion of the construction of the adjacent project, a comprehensive review of housing damage and settlement of deformation and settlement of the adjacent construction of the impact of housing, if necessary, the structural testing and safety assessment, proposed reinforcement measures proposed to submit the detection and monitoring summary report.