AllRounder.ai
Chapters in this course

Enrol to start learning

Reading is open to everyone. Enrolling is free, and it is what unlocks the audio lessons, practice tests and progress tracking.

Enrol free

9. Earth Moving Equipment-Scrapers (Part-2)

The lecture discusses the operational aspects of scrapers in civil engineering, focusing on productivity estimation and balancing the number of scrapers and pushers. It explains key concepts such as swell factor, machine weight, and resistance encountered during operations. The necessity of optimizing operations to improve productivity and reduce production costs is emphasized.

Sections

Earth Moving Equipment-Scrapers (Part-2)

This section elaborates on the productivity estimation of scrapers, cycle time calculations, and the interplay between scrapers and pushers in construction operations.

1 Section Overview

Start current section content and materials

Introduction

This section introduces and explores the fundamental concepts and operations involved in earth-moving equipment, specifically scrapers and pushers.

2 Section Overview

Start current section content and materials

2.1 Overview of Previous Lecture

This section reviews the previous lecture on the productivity estimation and components of scrapers in earth moving equipment.

Productivity Estimation of the Scraper

This section focuses on the estimation of productivity for scrapers, including calculations involving material properties, machine capacities, and operational efficiencies.

3 Section Overview

Start current section content and materials

3.1 Problem on Productivity Estimation

This section focuses on productivity estimation for scrapers in construction, detailing cycle times, resistance on haul routes, and optimizing the number of scrapers and pushers.

3.2 Material Characteristics

This section explores the characteristics of earth-moving equipment, focusing on scrapers and their productivity estimation.

3.3 Swell Factor Considerations

This section discusses the significance of the swell factor in estimating the productivity of scrapers, focusing on how pushing and material compaction affects calculations.

3.4 Loading and Operating Conditions

This section discusses the productivity estimation, operational safety, swell factors, and balancing of scrapers and pushers in earthmoving operations.

Haul Route and Resistance

This section examines the haul route characteristics and the resistance encountered by scrapers and pushers in construction operations.

4 Section Overview

Start current section content and materials

4.1 Description of Haul Route

This section discusses the various factors that affect the description and analysis of haul routes for scrapers in construction.

4.2 Rolling Resistance Analysis

This section focuses on rolling resistance in earthmoving equipment, particularly scrapers, and its implications on productivity and operational efficiency.

4.2.1 Section-wise Resistance Analysis

This section focuses on analyzing the productivity estimation and resistance analysis of scrapers in earth-moving operations.

Cycle Time Calculations

This section covers cycle time calculations related to scrapers in earth moving operations, including productivity estimation and balancing machinery.

5 Section Overview

Start current section content and materials

5.1 Travel Time Calculation

This section focuses on calculating travel time within earthmoving operations, specifically using scrapers and pushers, emphasizing productivity and cycle time considerations.

5.2 Cycle Time for Scraper and Pusher

This section outlines the cycle time for scrapers and pushers, focusing on productivity estimation and the balance of interdependent machines.

Balancing Scraper and Pusher Operations

This section explains the significance of balancing scraper and pusher operations to optimize productivity in earth-moving operations.

6 Section Overview

Start current section content and materials

6.1 Balancing Number of Scrapers

This section discusses the interdependence between scrapers and pushers in construction, focusing on productivity estimation and balancing their numbers to optimize machine efficiency.

Learning Objectives

  • The swell factor increases by 10% for push-loaded scrapers due to additional pressure from the pusher.

  • It's crucial to check the load of the scraper against its safe operating weight to prevent machine abuse.

  • Balancing the number of scrapers and pushers can minimize waiting time and enhance overall productivity.

Key Concepts

Swell Factor

The ratio of loose dry unit weight of material to bank dry unit weight, which indicates how much a material expands when disturbed.

Gross Weight

The total weight of the machine including its empty weight plus the weight of the load it carries.

Resistance

The total force opposing the movement of the scraper, including rolling and grade resistance, which affects its operational efficiency.

Cycle Time

The total time for a machine to complete one full cycle of operation, including loading, hauling, and unloading.

Practice Exercises

Total Questions

2

Estimated Time

4 min

Passing Score

70%

Instructions

  • Read each question carefully
  • You can use hints if you need help
  • Complete all questions before submitting

Get your answers marked and your progress tracked

Enrol free