First, the understanding of dangerous houses

      1, the number of dangerous houses is alarming: if the housing safety appraisal is carried out on the houses built before the 1990s, the actual number of dangerous houses will be far greater than the so-called "listed dangerous houses".
      2, the current dangerous house appraisal standard does not fully reflect the degree of danger of the house: the current dangerous house appraisal only has the standard of dangerous components, there is no standard of component failure. If the resistance effect ratio of the component is 0.4, 0.5, 0.6, 0.7, 0.8, the danger degree of the component is very different, and the dangerous house does not mean that the house will collapse, and the dangerous house has been identified as a dangerous house, and it has not collapsed for 20 years.

     3. At present, Grade C and D dangerous houses defined by the identification code of dangerous houses are divided by the percentage of dangerous components, and the high proportion is grade D, followed by grade C, which has nothing to do with the location of dangerous components, and the actual house collapse is closely related to the location of dangerous components. If the corner bearing capacity of the building is seriously insufficient, it is likely to lead to the collapse of the building; If the bearing capacity of the middle part is also insufficient, because of the multi-direction constraints, the house will not necessarily collapse after stress redistribution.

      4, China’s residential housing, illegal decoration is more serious, the security of the house has a great impact.

Second, the role of dynamic monitoring of housing safety

      There are signs before the collapse of the house, and dynamic monitoring can find dangerous signs in time, give early warning in time, take timely measures, and strive to achieve the goal of "as far as possible not to fail the house and zero casualties in the collapsed house".

Third, the content of dynamic monitoring of housing safety

      1, comprehensive survey well classification: check the surrounding environment, the basic situation of the structure, apparent damage, renovation and demolition, according to the degree of the house is graded, different levels of different frequency for dynamic monitoring.

      2, daily dynamic monitoring: ① find structural cracks and monitor the change of cracks; ② Find the weak point of the house structure; ③ Find whether there are new broken walls and decoration. ④ House settlement and tilt monitoring.

      3, decoration inspection: ① inspection found decoration; ② door-to-door publicity of house safety decoration knowledge to prevent damage to the original structure; ③ Tracking and monitoring in the decoration process; ④ the damaged structure requires recovery.

      4, emergency inspection: extreme weather, emergency, temporary safety inspection and emergency disposal of dangerous houses.

      5. Short-term collapse risk assessment: short-term collapse risk assessment for houses with large safety hazards.
      6. Assist letters and visits and complaints.
      7. Publicity and training: professional training on housing safety knowledge and publicity of housing safety knowledge for managers or residents.
      8, establish house safety inspection management system, establish house safety electronic files, real-time upload house safety situation.
      9. Prepare monthly and annual dynamic monitoring reports on housing safety, and summarize the results of all housing safety dynamic monitoring.

Relevant achievement

(1) A dynamic monitoring system for house safety has been established
(2) Participated in compiling the Guide for Dynamic Monitoring of Housing Safety issued by Ningbo Municipal Construction Commission
(3) Participated in the compilation of "Guidelines for Dynamic Monitoring of Housing Safety" of PICC Ningbo Branch
(4) The Assessment Standards for the Collapse Risk of brick-concrete Buildings were prepared.
(5) Participated in the compilation of Ningbo City "Yinzhou District Residential illegal decoration Structure repair General Map"
(6) Edited the local rules for engineering construction of Ningbo, "Technical Guide for Simple Repair of Common Defects of Existing Houses in Ningbo"