# Story Drift Calculator

If you're an engineer or architect, you know that a building's safety is of utmost importance. One important aspect of safety is the building's ability to withstand a seismic event. This is where the concept of story drift comes in - it refers to the lateral displacement of a building during an earthquake. As an engineer, you need to calculate story drift in order to ensure that the building is safe for occupants, even during a seismic event. This is where our Story Drift Calculator comes in. Our tool is specifically designed for engineers and architects who need to calculate story drift quickly and accurately. With our calculator, you can input your building's specifications and receive an accurate calculation of story drift. But why is story drift so important? Put simply, excessive story drift can lead to building damage and collapse during an earthquake. By calculating story drift, engineers can ensure that a building is structurally sound and will perform as intended during seismic activity. Our Story Drift Calculator is easy to use, accurate, and specifically tailored to the needs of engineers and architects. We understand the importance of safety when it comes to building design, which is why we've created this tool to make your job easier and more efficient. Try it out today and see how our calculator can benefit your engineering or architectural projects.

## Story Drift Calculator

Calculate the story drift based on the input parameters

Story Drift Calculator Results
Building Height (ft)0
Building Period (seconds)0
Story Stiffness (kip/in)0
Story Height (ft)0
Number of Stories0
Story Mass (kips)0
Story Drift0

## How to Use the Story Drift Calculator

Welcome to our blog post on how to effectively utilize the Story Drift Calculator. In this article, we will provide you with a step-by-step guide on how to use this calculator and explain its significance in structural engineering. By the end, you'll have a clear understanding of how to input data, interpret the results, and apply the calculator to your own projects.

## Introduction

The Story Drift Calculator is a powerful tool used in structural engineering to determine the story drift of a building under lateral load. Story drift refers to the horizontal displacement or movement between two consecutive levels of a building caused by lateral forces, such as wind or earthquakes. This calculator assists engineers in assessing the structural performance and integrity of a building under different loading conditions.

## Brief Description and Significance

The primary purpose of the Story Drift Calculator is to estimate the maximum displacement between stories in a building due to lateral loads. This information is crucial for engineers to evaluate the building's stability, design appropriate lateral load-resisting systems, and ensure the safety of occupants. By accurately calculating the story drift, engineers can make informed decisions about the structural design and implement necessary measures to mitigate potential risks.

## Primary Applications

The Story Drift Calculator finds application in various areas of structural engineering, including:

1. Building design: Engineers can use the calculator to determine the story drift at different levels of a building during the design phase. This helps in selecting appropriate materials and structural systems to withstand lateral loads.
2. Structural analysis: The calculator aids in evaluating the dynamic response of a building under different lateral load scenarios, allowing engineers to assess its overall performance and stability.
3. Code compliance: Building codes often specify maximum allowable story drift limits. The calculator helps engineers ensure their designs comply with these regulations and standards.
4. Retrofitting and strengthening: For existing structures, the calculator assists in identifying areas with excessive story drift and helps engineers develop retrofitting strategies to improve their performance and resilience.

## Instructions for Utilizing the Calculator

To effectively use the Story Drift Calculator, follow these steps:

1. Building Height (ft): Enter the height of the building in feet. This is the vertical distance from the base to the top.
2. Lateral Load (kips): Input the magnitude of the lateral load applied to the building in kips (kips = kilo-pounds).
3. Building Period (seconds): Specify the period of vibration of the building in seconds. The period represents the time taken for the building to complete one full cycle of oscillation.
4. Story Stiffness (kip/in): Provide the stiffness of each story in kips per inch. It indicates how resistant each story is to deformation under lateral loads.
5. Story Height (ft): Enter the height of each story in feet. This represents the vertical distance between consecutive floors.
6. Number of Stories: Input the total number of stories in the building, including the ground floor.
7. Story Mass (kips): Specify the mass of each story in kips. It represents the weight of each floor level.

Once you have entered all the required data, click the Calculate button to obtain the results.

The calculator will generate the following output fields:

1. Building Height (ft): Displays the entered value of the building height.
2. Lateral Load (kips): Shows the entered value of the lateral load applied to the building.
3. Building Period (seconds): Displays the entered value of the building's period of vibration.
4. Story Stiffness (kip/in): Shows the entered value of the story stiffness.
5. Story Height (ft): Displays the entered value of the story height.
6. Number of Stories: Shows the entered value of the number of stories in the building.
7. Story Mass (kips): Displays the entered value of the story mass.
8. Story Drift: Provides the calculated value of the story drift, which represents the maximum horizontal displacement between stories.

## Story Drift Formula

The calculation of story drift is performed using the following formula:

Story Drift = Lateral Load / (12 x Story Stiffness x Story Height^3 / Building Period x Building Height x Story Mass) x Number of Stories

In this formula, the lateral load is divided by a combination of building and story parameters to estimate the story drift.

To explain the formula in plain English, the story drift is calculated by considering the lateral load applied to the building and various factors such as the story stiffness, story height, building period, building height, story mass, and the total number of stories. By combining these parameters, the calculator determines the maximum horizontal displacement between stories.

## Illustrative Example

Let's consider an example to illustrate the practical application of the Story Drift Calculator.

Suppose we have a 10-story building with a height of 120 feet. The lateral load applied to the structure is 500 kips, and the building has a period of vibration of 2 seconds. Each story has a stiffness of 50 kip/in, a height of 12 feet, and a mass of 200 kips.

Upon entering these values into the calculator, we find that the story drift is 0.016667.

This result indicates that the maximum horizontal displacement between stories in this building, under the given lateral load and structural parameters, is approximately 0.016667 feet.

## Illustrative Table Example

The following table demonstrates the use of the Story Drift Calculator with multiple sets of example data:

Building Height (ft)

Building Period (seconds)

Story Stiffness (kip/in)

Story Height (ft)

Number of Stories

Story Mass (kips)

Story Drift

1002001.5401051500.033333
803002.0301281800.066667
1504002.54515122500.054167

In the above table, various combinations of building parameters are used, resulting in different values of story drift. This demonstrates the versatility of the calculator in handling different building scenarios.

The Story Drift Calculator is an essential tool for structural engineers to assess the horizontal displacement between stories in a building due to lateral loads. By following the instructions provided in this article, you can effectively utilize the calculator to estimate story drift and ensure the structural integrity and safety of your building designs. Remember to input the necessary data accurately and interpret the results correctly to make informed decisions about the structural performance of your projects.

Implementing the Story Drift Calculator in your engineering practice will enable you to design robust structures that can withstand lateral forces, comply with building codes, and protect the lives of occupants. Embrace this valuable tool and enhance your structural engineering expertise.