Material procurement, sequencing of operations, site logistics, project schedule, as well as the technical aspects of the project are critical drivers in selecting equipment for building projects.
PLANNING Contractors working on projects in urban environments must mitigate the effect of nuisances on project neighbors.
Various pieces of equipment can be used to support construction processes. Crane PLANNING Concrete placement boom
SITE LAYOUT 1.Site size compared to building size and configuration 2.Location of adjacent roads, buildings, and utilities A contractor must consider many factors when laying out a site to support construction operations:
SITE LAYOUT 3.Soil conditions and excavation requirements 4.Construction sequence and schedule 5.Location of utilities 6.Equipment requirements 7.Material quantity, storage, and delivery.
SITE LAYOUT 8.Worker parking 9.Tool and equipment storage. 10.Construction operations facilities and trailers. 11.Sanitary facilities
The job-site layout is key in enabling the subcontractors to operate effectively and efficiently. SITE LAYOUT
Subcontractors need information from the General Contractor and have to provide information to the GC about: Schedule Sequence of other trades Crane size and provider Placement of crane, job trailers, storage areas, and laydown areas
SITE LAYOUT The goal of site layout is to optimize operational processes steel erection, concrete forming, and placement of the concrete in the forms. The GC and the subs seek to keep the number of crane locations at a minimum.
SITE LAYOUT Occupational Safety & Health Administration (OSHA) Standard 1926.752 places specific duties on the General Contractor (called the controlling contractor by OSHA). 1926.752(c) Site layout.
SITE LAYOUT Occupational Safety & Health Administration (OSHA) Standard 1926.752 places specific duties on the General Contractor (called the controlling contractor by OSHA). 1926.753(d) Working Under Loads
LIFTING AND SUPPORT EQUIPMENT Typical equipment used for concrete and steel erection includes: Cranes Manlifts Generators Welding equipment Air compressors
MOBILIZING THE CRANE Crane mobilization involves transporting the crane to the job site and preparing the crane for use.
LIFT PLANNING All crane hoisting must be planned. In the case of general lifts that do not involve critical lifts there can be a single set of planning guidance.
GENERAL LIFTS General Lift Plans cover activities such as unloading miscellaneous supplies and the plan would Require a designated lift director Require that a signal person is assigned and identified to the crane operator
GENERAL LIFTS General Lift Plans cover activities such as unloading miscellaneous supplies and the plan would Require that the weight of the load be known. Document lifting restrictions
PRODUCTIONS LIFTS Production lifts are repetitive-type lifts that do not fall under the classification of critical lifts. Their lift plans would modify the general lift plan and include: Provide a physical description of the items to be lifted (size, weight, shape, and center of gravity).
Production lift plans would modify the general lift plan and include: Describe the appropriate operational factors of the lifts, lifting and swing speeds, and crane travel path. Address lift hazards such as rigging and controlling access to the area under the hoisting path.
PRODUCTIONS LIFTS Production lift plans would modify the general lift plan and include: Identify lift restrictions that are over and above those of the General Lift Plan.
CRITICAL LIFTS Critical lifts require a specific lift plan. When the overall risk of a lift is assessed as being significant for whatever reason load weight, difficulty, complexity, multiple crane lift, restricted area the lift is classified as critical.
CRITICAL LIFTS When the overall risk of a lift is assessed as being significant multiple crane lift the lift is classified as critical.
CRITICAL LIFTS A critical lift plan will Identify the person in charge of the entire lifting operation. Identify the physical properties of the item being lifted, exact weight, dimensions, and center of gravity.
CRITICAL LIFTS A critical lift plan will Identify hoisting equipment by type, rated capacity, boom length, and configuration. Identify required rigging including capacity of items and accessories. Identify the travel path of the load by the required hoisting, swinging, and travel motions of the crane.
CRITICAL LIFTS A critical lift plan will Include an analysis of weather factor impacts (wind, temperature, visibility) and state weather controlling limits. Assign a signaler and provide continuous communications between the signaler and the crane operator.
DELIVERY OF STRUCTURAL COMPONENTS Structural steel and precast concrete members are usually delivered to the job site by the truckload. Concrete members are usually lifted from the truck and placed directly in the structure. It is common practice, however, to unload the steel from the trucks and place it in a laydown area.
STEEL ERECTION The American Institute of Steel Construction Code of Standard Practice states that “The Erector shall be responsible for the means, methods and safety of erection of the Structural Steel frame.”
STEEL ERECTION The two primary safety concerns are fall protection for the personnel doing the erecting and stability of the frame during the erection process before all elements of the structure are in place. Tied off
TILT-UP CONSTRUCTION Concrete tilt-up wall construction is a method of building concrete interior and exterior walls without the use of vertical formwork and that minimizes the required duration of lifting crane equipment time.
TILT-UP CONSTRUCTION PANEL LAYOUT Each panel has a particular function and place where it belongs in the structure. The goal is to place the panels as close as possible to the spot where they will be erected.
TILT-UP CONSTRUCTION FORMS Steel “ L ”-shaped forms are usually used. Anchor bolts through the base of the “ L ” are used to keep the forms in place during the concrete placement.
TILT-UP CONSTRUCTION CONCRETE PLACEMENT Concrete is often placed using a concrete pump truck. Using a handheld remote to control the boom and the flow of concrete, the operator, can easily maneuver the boom trunk as needed.
TILT-UP CONSTRUCTION ERECTING PANELS Hoisting the panels requires a mobile crane. Since the crane is a major cost item, it is imperative that the proper lifting sequence be followed so that the crane can move as many panels as possible without having to be repositioned.
TILT-UP CONSTRUCTION ERECTING PANELS Usually a spreader bar, with evenly spaced pulleys having wire-rope lifting bails, is used for the picks.
TILT-UP CONSTRUCTION ERECTING PANELS Once the panel is leveled and plumbed, the braces are attached to the slab.
CONTROL OF CONSTRUCTION NUISANCES The major nuisances associated with construction are noise, vibration, dust, and illumination for nighttime work. Contractors working on projects in urban environments must mitigate the effect of such nuisances on project neighbors.