揚重用クレーンの配置計画に関する研究その 1

Abstract

Following the increasing requirements of this society, the construction projects become much more complex and much more costly in recent years. However, "Decision-Making" during planning and managing stages are still mostly depended on so called "Experience", "Intuition" or "Hunch". The fact is that there is a lack of rational approaches for Decision-Making which have been developed from management science applications, thus, the decisions might turn out entirely different by different parties. Although, the management science applications might not solve all the present Decision-Making Problem, but, it is definitely necessary to make efforts on logical Decision-Making approaches. This study is to try to define a fomula for one of the most important part of construction plan, "THE MOST SUITABLE CRANE DEPOSITION PLAN". It tries to propose the algorithm which can find out the less expensive crane-cost (total cost of the hire, assembling and demolishing of cranes) by arranging the combination use of different cranes, such as truck-crane, crawler crane, rail-mounted tower crane, tower crane, etc. The approaches will be described as follows; 1).…Examine the constructability of mobile-cranes. In lifting capacity, working range, possible workable height, etc. 2).…Define the crane deposition plan which is operationable at lowest cost by fixed type tower crane only as All-zero-one Integer Programming Problem. Examine the problem solution. Then, take Set Covering as special condition, examine the algorithm diminuting All-zero-one Integer Programming Problem. 3).…Find out the constructable crane list and floor numbers from 1) and 2). Then, set the selected crane and its cost from the first floor to the top floor of a project as Dynamic Programming Problem, "SHORTEST PATH PROBLEM", and explain the solutions. The applicability of this model solution will be concluded as follows; 1). Even under the same floor-plan and lifting-load condition, the crane deposition may be changed by floor numbers of the project. 2). Even under the same floor-plan and floor-numbers condition, the crane deposition may be changed substantially by the different lifting-load. 3). Under the present crane deposition plan, the cranes for the first floor to the top floor were usually set up by the very beginning of the project, however, this model solution shows a substantial difference. 4). The crane deposition plan might be influenced by the working period of each floor, that is because it might affect factors of assembling, demolishing and the hire of cranes. 5). Directly speaking, the conclusion shows that it is more beneficial at first to use the crane with the lower hire-cost, and replace it when it reaches its limitation of constructability.