Process of Investigation

• Before undertaking a survey , it is imperative that the purpose , nature & scope of survey be ascertained .
• After an agreement is reached between the Client & the Investigator , the Investigator should confirm in writing the following instructions :

1. Purpose of survey
2. Agreed date of commencement .
3. Expected date of completion
4. Scope of work .

Confirmation Letter :

1. Purpose of survey : whether structural survey , valuation , redevelopment , feasibility study etc .
2. Agreed date of commencement .
3. Expected date of completion .
4. Scope of work : statement of investigator's intentions covering a range of relevant matters such as extent of inspection , extent of opening up of the structure , any limitation of liabilitty by the investigator , basis of calculation of professional fees & other reimbursement .

The process of investigation consists of the following :

1. Preliminaries
2. Visual Inspection
3. Testing & Monitoring
4. Exploratory Works

1. Preliminaries
This consists of
a. Documentation survey : information on building structure & maintenance records
b. Site visit : to assess practical restrictions such as access & safety requirements .

Important documents are :
1. Design & as - built drawings
2. Specifications
3. Adjacent buildings records .
4. Suppliers records
5. Contractor test records during construction
6. Records of defects & repairs
7. Past & present usage of the building
8. Design loading &
9. Any subsequent alterations .

2. Visual Inspection

• Careful scruitiny of the building based on human sense of sight , touch , hearing & smell .
• Use basic tools such as magnifying glass , hammer , scrappers , mirrors & binoculars
• Take photographs for future reference .
• Conduct interviews with occupants & maintenance personnel .
• From visual inspection , valuable information such as workmanship , structural serviceability & material deterioration can be obtained .
• The one doing the visual inspection muyst be knowledgeable in the area .
• If no defects are detected or suspected , confirmatory tests could be carried out more economically on critical locations only .

3. Testing & Monitoring

• Testing to be decided after visua inspection
• TYpes of available test :

- Non - desctructive test
-Semi-destructive test
-Destructuve test
-Chemical analysis of material
- Physical analysis of material
- For large buildings , testing must be selective critical zones or memebrs could be sampled for testing purposes .
- A combination of destructuve & non- destructive methods should be used together to achieve a more consistent & accurate result .
- Accessibility must also be considered  together with the safety of the occupants , site personnel & general public .
-Monitoring is a useful methods  of assessing the movement of building structures over a period of time . THis can be done by measuring the widths of fracture or by taking vertical alignment readings of the structure with a theodolite from a datum position .


4. Exploratory work

• The techniques of removing obstructions to facilitate a closer inspection of hidden parts include

- Excavation works to reveal the depth , size & condition of foundations .
- Selective hacking of structural memebrs to expose reinforcement .
In every case , damage will be caused egfarded as the last resort in clarify causes & only employed where everthing else has failed .
- In some cases  , exploratory instrucments will assist in reducing disturbance to a minimumm .