Definition of Design Period | Why Design Period is Provided | Factors Affecting Design Period | Design Period Values

All About Design Period

Definition of Design Period:

Design period could be defined as the number of years in the near future in which the supply will surpass the demand. Or, It is the number of years in the near future in which the given facility is obtainable to satisfy the demand.

Why Design Period Is Provided?

Why Design Period Is Provided

The main reasons behind providing Design Periods are:

  • It is prodigiously strenuous or unfeasible to produce frequent.
  • It is affordable to supply one mammoth unit in lieu of constructing a variety of bijou ingredients.


Factors Affecting Design Period:

Factors affecting Design Period are given below. Following are some aspects which act on the Design Period of the structure:

  • Availability of Funds.
  • Life of the structure.
  • Ease or Difficulty in Extension.
  • Rate of Increment.
  • Lead Time.
  • Economy of Scale.
  • Interest Rates.
  • Quality of Material.
  • First Cost.

1. Availability of Funds-

If funds are obtainable, one must hold on to a smaller design period.

2. Life of Structure-

Life of structure is that the number of years in the near future in which the design period is physically & practically suitable to bestow the intended amenity.

So it is always ought to be less than a lifetime of structure.

Factors Affecting Design Period Type of Pipe Average Service Life
Steel Pipes 25 – 50 Years
Cast Iron Pipes 100 Years
Concrete Pipes 75 Years

3. Ease or Difficulty in Extension-

For the projects whose augmentation is unquestionably feasible, it’s generally kept low. For instance, we are capable of inaugurating new tube-wells at any time since we don’t require to install all tube wells which might be required after 20

  • Tubewell: Easy to drill.
  • Treatment Plant: Easy to enlarge.

But for the projects whose augmentation is strenuous, their design period is kept sizeable. For instance, dams and reservoirs cannot be augmented

Adroitness and difficulty that’s likely to be faced in expansions, if undertaken at future dates. For instance, vigorous expansions mean choosing a finer value of the design period.

4. Rate of Increment-

If the speed of growth is lofty, then for that region dwarf design period is required. Anticipated rate of population growth, including feasible shifts in communities, industries, and commercial inceptions.

For instance, if the speed of increase of population is comparatively sloth, a better figure for the design period could also be chosen.

5. Lead Time-

It is the time from the outset of a project to its completion. Design period should be greater than the interval.

Lead Time = Time for Design of Project + Construction Time

6. Economy of Scale-

  • The decrease in monetary value parallel to the increase in a facility is thought of as an Economy of Scale.
  • If the economy of scale is little, smaller design periods are used.
  • It’s economical to make an oversized structure, for an extended design period.

7. Interest Rates-

  • If charge per unit is bijou, the lofty value of design period is also economically possible.
  • The rate of interest depends on the borrowings and also the ancillary money which needs to be invested.
  • Amount and availability of ancillary investment likely to be incurred for extra arrangements. For instance, if the funds aren’t available, one should keep a bijou design period.

8. Performance Time-

  • Structures are checked under working conditions in due course, which mustn’t be considered in the design period. During this point, it’s not providing facility to the community.

9. Quality of Material-

  • Design period mustn’t be longer than the lifetime period of the material utilized in the installation project.
  • The quantity of years of which a provision is formed in designing the capacities of the varied modules of the water system scheme is recognized as design period.

10. First Cost-

  • In case of High first cost and High Rate of interest, design period should be brief, so that the aggregate cost of the project should not be disseminated to present population e.g. Houses.

Design Period Values:

Water system projects, under a standard state of affairs, could also be designed for a design period of 30 years. This 30 year period may, however, be amended in relevance to specific units of the project, depending upon:-

  • The useful lifetime of the component facility.
  • Ease in polishing off extensions when required.
  • Rate of interest is in order that expenditure, far ahead of utility, is avoided.

The design period for designing the assorted components of a facility project is provided in the ensuing table:

Item Design Period in Year
Storage by Dams 50 year
Intake Works 30 year
Pumping

1. Pump House

2. Electric Motors and Pumps

 

30 year

15 year

Water treatment units 15 year
Pipe connection to the sundry treatment units and other small paraphernalia. 0 year
Raw water and clear water transporting units 30 year
Clear water reservoirs at the head works, balancing tanks, and service reservoirs 15 year
Distribution system 30 year

Also, Read: What Is Limit State Method | Assumption in Limit State of Collapse | Limit State Design | What Is Working Stress Method | Assumptions in Working Stress Method | Working Stress Method of Design

What Are Design Period and Return Period for Design Conditions?

What Are Design Period and Return Period for Design Conditions

  • Design life means the rock bottom span of a structure that is predicted to last.
  • The longer is the design life; the further is the cost of a project.
  • Therefore, in choosing the design life for a structure, engineers ought to inspect the design life which spawns an economical project without relinquishing the desired function.
  • In a selection of return periods of particular design conditions, winds, waves, etc., one ought to consider the connotations of over-expenditure.
  • In fact, there are ordinarily no paramount or maximum values of those design conditions, and its selection is anticipated on the probability of expenditure which is set forth to return period.
  • Hence, design life might not be indistinguishable from to the return period of design conditions because their selections are succored on different considerations.

Also, Read: Pile Cap Design | Pile Cap Construction | Piles Structure | Pile Cap Foundations | Square Piling Caps | Pile Cap Reinforcement


Short Note

Definition of Design Period:

It is the number of years in the future for which the proposed facility would meet the demand of the community. Or. This is the period into the future. Which estimation is to be made.

What Is Design Period?

The number of years of which a provision is made in designing the capacities of the various components of the water supply scheme is known as design periodDesign period cannot exceed the useful life of the component structure.

Factors Affecting Design Period:

Factors Affecting Design Period are as follows.

  • Availability of funds If funds are not available, one has to keep a smaller design period.
  • Interest rates If interest rate is small, a higher value of the design period may be economically possible.

Design Period Values:

For example, if the interest rate is small, a higher value of the design period may be economically justified and, therefore, adopted. Design Period Values: Water supply projects, under normal circumstances, may be designed for a design period of 30 years.

Design Period

Design Period means the period of time commencing upon the Design and Construction Works Commencement Date to and including the date on which the Design is completed.

Why Is Design Period Required?

The number of years of which a provision is made in designing the capacities of the various components of the water supply scheme is known as design period. Design period cannot exceed the useful life of the component structure.

What Is Design Period in Hydrology?

In hydrology, design return periods vary typically from 10 yr to 100 yr, and in countries (or places) where the Probable Maximum Precipitation (PMP) has not been defined, up to 10,000 yr.

What Does Design Period Mean?

Design Period means the period of time commencing upon the Design and Construction Works Commencement Date to and including the date on which the Design is completed.

What Is Design Period in Designing Water Supply Schemes?

Water Supply projects may be designed normally to meet the requirements over a thirty-year period after their completion. The time lag between design and completion of the project should also be taken into account which should not exceed two years to five years depending on the size of the project.

What Do You Mean by Design Period in Water Supply & Treatment?

Design period is defined as the future period for which a provision is made while planning and designing the water supply programs. Usually, 15 to 20 years is adopted as design period.

What Does Period Mean in Architecture?

There is no binding definition, but generally speaking the term period is used for buildings that pre-date the First World War. However, as time marches on and the decades mount, there is a strong argument for including later 20th-century architecture, such as Art Deco.

What Is Meant by Design Period?

The number of years of which a provision is made in designing the capacities of the various components of the water supply scheme is known as design period. Design period cannot exceed the useful life of the component structure.

The Design Period for a Water Supply Project Is Taken As

Water Supply projects may be designed normally to meet the requirements over a thirty-year period after their completion. The time lag between design and completion of the project should also be taken into account which should not exceed two years to five years depending on the size of the project.

Design Period of Water Supply

The Design period for the design of a water supply project generally takes as 20-30 years.

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