## Blog

The Latest Engineering Trends and Issues

*Click the content to move to the section

In July 2020,  we hosted a webinar, “How I Design Bridges: Static Analysis of Cable-Stayed Bridges," by Sam Li, Senior Structural Engineer/CaSE Design, Australia.

Mr. Sam Li goes through the complete process of performing static analysis of cable-stayed bridges, and we believe this knowledge will help various global structural engineers with their ongoing projects.

# Dynamic Analysis of Fan, Semi-Fan, and Harp Type of Cable-Stayed Bridges

While modeling cable-stayed bridges, the different types of cable arrangements such as Fan, Semi-Fan, and Harp type is often considered. Since they vary in cable arrangement, the pretension in the cables is different and the deflection, bending moment, and stresses vary in the bridge. It then becomes prudent to choose the best arrangement for a more optimized design leading to lesser cost and increased safety.

Figure 1: Cable Stayed Bridge

In this article, we present, in a concise way, the modeling of a Cable-Stayed Bridge in midas civil with three different cable arrangements. Furthermore, Response Spectrum analysis is carried out on the models to study the Dynamic Responses of the three arrangements.

## 1. Introduction

Depending on the purpose, a bridge can be planned in various shapes. To enable a large amount of transportation, a bridge designer can apply several design considerations to a bridge design. Let’s look at one of them.

A double-layer bridge provides more space through the double-layer girder to transport vehicles, trains, or pedestrians. This type of girder has enough vertical clearance to carry them. Therefore, it could make clearance issues under the bridge, and also it could make aero stability issues. Nevertheless, the double-layer girder can be one of the available options for a bridge in areas where heavy traffic is expected.

## 1. Introduction

Depending on the purpose, a bridge can be planned in various shapes. To enable a large amount of transportation, a bridge designer can apply several design considerations to a bridge design. Let’s look at one of them.

A double-layer bridge provides more space through the double-layer girder to transport vehicles, trains, or pedestrians. This type of girder has enough vertical clearance to carry them. Therefore, it could make clearance issues under the bridge, and also it could make aero stability issues. Nevertheless, the double-layer girder can be one of the available options for a bridge in areas where heavy traffic is expected.

## An inspiration to a generation of engineers and a very costly learning opportunity

Prestressed concrete is a structural material that allows for predetermined engineering stresses to be placed in members to counteract the stresses of loads. It combines the high-strength compressive properties of concrete with the high tensile strength of steel. These prestressed concrete girder bridges are currently used in bridge construction all over the world. Research on materials and superstructures of bridges has shown that prestressed concrete girder bridges have the longest life span and require less maintenance than other bridges. Furthermore, these bridges are increasingly being used due to their aesthetic versatility, strength, quality, and reduced construction time.

In this webinar, we will follow a step-by-step modeling example for the transverse analysis using various functions in midas Civil. Additionally, we will provide information about the usage and meaning of each function.

In this webinar, we will introduce the midas Civil application of the transverse analysis of prestressed concrete box girder in the cable-stayed bridge.

This case study highlights

## 4. Post-processing and Other Modeling Applications

The example structure below is the Saemangeum bridge in South Korea. This project is a preliminary design. The structure is a cable-stayed bridge with concrete superstructures, pylons, and piers. The superstructure is composed of pre-stressed concrete girders. The transverse analysis was carried out in midas Civil.