The purpose of this research is to study the construction safety system for working at height. The safety system for working at height in this research is predetermined by department of labour protection and welfare and safety and health at work promotion association (Thailand). The safety system composed of (1) safety policy (2) safety organization (3) prevention measure (4) risk analysis (5) training (6) safety inspection (7) accident report and (8) emergency planning. Since they had been used construction safety system for working at height in construction site. They have seen different number reduced from accident on site project. However the cost of construction project would have increases.For example building construction site project would taking more time to finished their project. Such as project A have costs increase 281385 baht Project B have costs increase 263648 baht and Project C have costs increase more 285413 bahtRespectively.

The purpose of this research is to study the construction safety system for working at height. The safety system for working at height in this research is predetermined by department of labour protection and welfare and safety and health at work promotion association (Thailand). The safety system composed of (1) safety policy (2) safety organization (3) prevention measure (4) risk analysis (5) training (6) safety inspection (7) accident report and (8) emergency planning.

The purpose of this research is to study the effect of a safety system provided for external wall plastering activity on productivity by studying a construction of commercial buildings. The safety system composed of (1) stable scaffolding system (2) providing clean and not slip walkways on the scaffold (3) installation of handrails not less than 0.90 meters in height along sides of the scaffold (4) installing safety nets around outside perimeters of the scaffolding (5) indicating working area (6) installing stairs (7) providing protection for people who works below (8) providing tools and equipments for transporting material which are safe and ready for using and (9) providing personal protective equipment for workers. Cost of the safety system is 79665 baht for a wall area of 1510 m2 or approximately 53 baht/m2. The prevention cost is quite high because it is an initial investment cost. However contractors could repeat theirs used on future projects. Productivity rates for prior and after the used of safety system are 1.16 and 1.13 m2/person/hr respectively. The productivity declines for approximately 3%. In addition our study found an impact of predecessor activity which is a brick laying activity. If brick walls are not well aligned and plumbed the working time for wall plastering could take longer for 8%. Meanwhile the wall plastering productivity could decrease for 11% and labor cost could increase for 12%.

The objectives for the study are the causes seeking and studying the critical level of problems for the construction project within the Rattanakosin Technology University; Salaya together with proposing the solution and the prevention as the guidance to manipulate the construction project within the university which may help to reduce the delaying problems. The study would use the data from questionnaires and the interview forms for the construction manager engineer foreman contractor and construction project committee who are working for the 14 constructing projects within the university. As for the data analysis the researchers would compare the critical levels and the frequency of each cause of the delay. The results showed that the Problem causes delays construction occurring in Rattanakosin Technology University; Salaya by simply selecting the S.I. 1 in 3 sequence ที่most valuable of each factor the resulting delays in construction divided into four main topics below 1. Man : of 6 factors the total number of 18 factors 2. Material : of 6 factors the total number of 18 factors 3. Machine : of 5 factors the total number of 18 factors 4. Method : of 6 factors the total number of 18 factors

The purpose of this research paper is to study the solid waste management to the following 3 lines of BTS Sky train construction projects: blue linered line and violet line.The study was carried out by distributing questionnaires to 22 randomly selected contractors on the site from Sino-Thai Engineering and Construction Plc. CKTC Joint Venture Co. SH-UN Joint Venture Co. and Unique Engineering and Construction Plc. The results of the survey showed that an average quantity of solid waste during the commencement ot the project and reached to x=2.54SD=0.80 during construction period. However the quantity lf solid waste was higher upon the termination of the project X=1.97 SD=0.72. For some managers the problems of solid waste were caused by planning and policy maling such as too much rush work unsuitable material management area and misleading materials planning. The other contributors to the problem were traced from operators material transportation to the site. Workers have a lack ot the expertise to work. Supervisors have a lack of monitoring and supervisory work. Supervisors training on waste management played a vital role in promoting solid waste management(X = 3.44 SD = 0.73).