4.1 DELAY DUE TO POOR SITE CONDITION
Its a job of planning department to neatly plan the construction activity on site. But mostly at the time of planning personnel dont anticipate the condition on site. They just assume the site condition positive to the work environment. There lies the reason for delay. Because actual site conditions are far worst that anticipated and not good for work. Here are some such examples on site which cause problem to work and become one of the major factors of delay of construction project.
A. EROSION OF SOIL
Photograph 2. 1 Erosion of soil: Source – Actual Site Yamuna Express way, Noida
Erosion controls prevent soils from being detached and carried away by wind or water; whereas sediment controls trap and filter out sediment that has already been introduced to site runoff. Erosion controls should always be your first line of defence in the wet season, followed by sediment controls. An effective combination of both types is required during the wet season.
During the dry season, typically sediment controls alone will enough.
Where there is a construction site or other open area, clearing, grading, excavating and other earth-moving activities make construction-site erosion control a necessity. Golf courses in the making, new building sites, vacant lots any open areas where rains land on unstable soil can produce not only massive headaches for contractors, builders, and landowners but massive fines and liabilities.
It can happen fast. Consider heavy storm water flowing over construction sites or other open areas picking up sediment, debris, and chemicals. Not only is aquatic life endangered, so too are the health and activities of animals and people who count on unpolluted waters for drinking, fishing, swimming, and other activities.
Photograph 2. 2 Dust problem on Site: Source – Actual photo. Yamuna Expressway, Noida
Heavy construction is a source of dust emissions that may have substantial temporary impact on local air quality. Building and road construction are 2 examples of construction activities with high emissions potential. Emissions during the construction of a building or road can be associated with land clearing, drilling and blasting, ground excavation, cut and fill operations (i.e., earth moving), and construction of a particular facility itself. Dust emissions often vary substantially from day to day, depending on the level of activity, the specific operations, and the prevailing meteorological conditions. A large portion of the emissions results from equipment traffic over temporary roads at the construction site. The temporary nature of construction differentiates it from other fugitive dust sources as to estimation and control of emissions. Construction consists of a series of different operations, each with its own duration and potential for dust generation. In other words, emissions from any single construction site can be expected (1) to have a definable beginning and an end and (2) to vary substantially over different phases of the construction process. This is in contrast to most other fugitive dust sources, where emissions are either relatively steady or follow a discernable annual cycle. Furthermore, there is often a need to estimate area wide construction emissions, without regard to the actual plans of any individual construction project. For these reasons, following are methods by which either area wide or site-specific emissions may be estimated.
C. SEDIMENTATION ON ROADWAYS
Sedimentation on roadways leads to the accumulation of the mud on the concrete or bituminous roads, which my caused because of mud came along with the tires of the trucks or may because of accumulation or water logging.
Photograph 2. 3 Sedimentation on Site access and internal roads
Proper planning of access roads to the site and within the site is essential to the efficiency of the project. Following goals are to be achieved
The roads must provide direct access to all points needing access.
Such points would include storage areas, insulation areas, and entries to the work point.
The access roads must be built solidly, to withstand the loads, the traffic and the weather conditions during the period of use.
Access roads must be placed during a time and in a location where they will not be moved or replaced. Underground utilities can disrupt the traffic on haul roads.
If the haul road is to be disturbed than alternate temporary roads are constructed.
Access roads should be appropriately constructed to the type of traffic that will be using them.
A roadway for public vehicle traffic has different requirement than that for a haul road for scrapers.
D. Access to the site
Normally these roads become permanent roads or street after word hence these must be constructed as per plan of municipality.
If a provision of these roads is there in contract, then they must be constructed before project starts.
Sometime these are constructed with separate schedule and they need till permanent roads are constructed mainly to divert traffic or to have alternate route to supply the materials and other items.
Adequate parking areas for construction employees need to be established and need to be close to access roads.
Access within site
The access roads within the site are rarely designed or defined by the construction documents, because they are the contractors responsibility.
Some occasions allow permanent internal roadway to be used during the construction phase, but these usually are constructed after the buildings and structures on the site.
The contractor should determine the location of these roads, how they will be used, and what type of roadway will be necessary.
E. INEFFECTIVE CONCRETE WASHOUT AREAS
Concretes versatility, durability, and economy have made it the worlds most used construction material. There are two by-products generated by the concrete and construction industry as a result of all the ready-mixed concrete used; concrete washout or waste and wash water. In order to emphasize the volume of by-products generated every year by the construction industry, we have compiled the estimated figures below which put into perspective the magnitude of this problem and the impact of improper containment measures and lack of recycling efforts on jobsites nationwide.
Photograph 2. 4 Ineffective Concrete washout areas: Actual Site photo ; Yamuna expressway , Noida
The amount of concrete washout material and wash water generated each year accumulates to:
34 times more concrete than was used to build the Sears Tower in Chicago (2 million cubic feet/72,000 cubic yards), the worlds tallest building until 1996 or,
enough concrete to build an 8-lane freeway system 175 miles long or,
nearly ? the amount of concrete used to construct the entire Hoover Dam
Enough water to provide a city of 50,000 for nearly three months
The most common discharge into our storm drains from concrete construction is the residue and contaminants from washing down equipment such as concrete trucks, pumps, mixers, chutes, hand tools and wheelbarrows. It also comes from other cementitious type products such as grout, mortar and stucco. Concrete or cementitious washout wastewater is caustic and considered to be corrosive with a pH near 12
F. INEFFECTIVE DRAIN INLET PROTECTION AND MAINTENANCE
To prevent sediment from entering storm drainage systems prior to permanent stabilization of the disturbed area and provide permanent protection for a storm drain after the drainage area is stabilized. Storm sewers which are made operational before their drainage area is stabilized can convey large amounts of sediment to natural drainage ways. In case of extreme sediment loading, the storm sewer itself may clog or lose a major portion of its capacity. To avoid these problems, it is necessary to prevent sediment from entering the system at the inlets. This practice contains several types of inlet filters and traps which have different applications dependent upon site conditions and type of inlet. Other innovative techniques for accomplishing the same purpose are encouraged, but only after specific plans and details are submitted to and approved by the permitting agency.
Photograph 2. 5 Blockage of the drain inlet
G. IMPROPER JOB SITE MANAGEMENT
Job site management is the term we refer for the actual layout of the working site. Lay-out of the site shows the position of all the equipments, materials, utilities, offices and in site path. Improper planning job site layout leads to obstructions in site operations, which inturn leads to delay. There are two major factors that come in this sector are as follows
H. Lack of Good Housekeeping Practices
Materials arriving on site are unloaded into what someone guesses to be the correct location. This practice may subsequently involve double or triple handling of material to move them to another place because, for example They have been stacked over a drainage run, or in the way of the scaffolding or too near the edge of a future excavation They are too far from where they are needed They are too far from hoist, or not within the radius of the crane, or a long way from the ramp They obstruct work traffic across the site They are too near the route of work traffic and may get damaged or soiled.
I. Material stores wrongly located
Materials arriving on site are unloaded into what someone guesses to be the correct location. This practice may subsequently involve double or triple handling of material to move them to another place because, for example
They have been stacked over a drainage run, or in the way of the scaffolding or too near the edge of a future excavation
They are too far from where they are needed
They are too far from hoist, or not within the radius of the crane, or a long way from the ramp They are too near the route of work traffic and may get damaged or soiled.
4.2 MATERIAL RELATED DELAY FACTORS
Changes in material types and specifications during construction
Damage of sorted materials
Delay in manufacturing materials
Escalation of material prices
Late delivery of materials
Poor procurement of construction materials
Poor quality of construction materials & Shortage of construction materials r
Above diagram is The Ishikawa Diagram(developed by Ishikawa), also known as the Fishbone Diagram or the Cause-and-Effect Diagram, is a tool used for systematically identifying and presenting all the possible causes of a particular problem in graphical format. The possible causes are presented at various levels of detail in connected branches, with the level of detail increasing as the branch goes outward, i.e., an outer branch is a cause of the inner branch it is attached to. Thus, the outermost branches usually indicate the root causes of the problem. The Ishikawa Diagram resembles a fishbone (hence the alternative name “Fishbone Diagram”), it has a box (the ‘fish head’) that contains the statement of the problem at one end of the diagram. From this box originates the main branch (the ‘fish spine’) of the diagram. Sticking out of this main branch are major branches that categorize the causes according to their nature.
A sample Ishikawa diagram is shown in Figure