Measurements and Traversing

Measurements and Traversing in Mining Surveying - II

I. Introduction

In mining surveying, accurate measurements and traversing are essential for various purposes such as determining the height and distances of accessible and inaccessible points, as well as establishing the coordinates and angles of different locations. This topic will cover the fundamentals of measurements and traversing in mining surveying.

A. Importance of Measurements and Traversing in Mining Surveying

Measurements and traversing play a crucial role in mining surveying for the following reasons:

• Determining the height and distances of accessible and inaccessible points helps in planning and designing mining operations.
• Traversing with a Theodolite on the surface and underground allows for accurate mapping and positioning of mining features.
• Checks on closed and open traverses ensure the accuracy and reliability of surveying data.
• Balancing traverses helps in identifying and correcting errors in measurements.

B. Fundamentals of Measurements and Traversing

Before diving into the specific methods and procedures, it is important to understand the basic principles of measurements and traversing in mining surveying:

• Measurements involve determining the height and distances of points using various techniques and instruments.
• Traversing refers to the process of measuring angles and distances between consecutive points to establish a network of control points.
• Theodolite is a commonly used instrument for traversing, which allows for precise angle measurements.

II. Measurements

Measurements in mining surveying can be categorized into two types: measurements of height and distances of accessible points, and measurements of height and distances of inaccessible points.

A. Measurements of Height and Distances of Accessible Points

When it comes to measuring the height and distances of accessible points in mining surveying, several methods can be employed:

1. Methods for Measuring Height

• Spirit Level: A spirit level is used to determine the difference in height between two points by measuring the inclination of a leveling staff.
• Stadia Method: This method involves using a stadia rod and a theodolite to measure the vertical angle and the horizontal distance simultaneously.
• Trigonometric Leveling: Trigonometric leveling utilizes trigonometric principles to calculate the height difference between two points based on the measured horizontal distance and vertical angle.

2. Methods for Measuring Distances

• Tape Measure: A tape measure is a simple and commonly used tool for measuring distances between points.
• Electronic Distance Measurement (EDM): EDM instruments use electromagnetic waves to measure distances accurately.
• Total Station: A total station combines the functionality of a theodolite and an EDM, allowing for simultaneous angle and distance measurements.

B. Measurements of Height and Distances of Inaccessible Points

In mining surveying, there are situations where certain points are inaccessible, such as underground areas or hazardous locations. In such cases, alternative methods are employed to measure the height and distances:

1. Methods for Measuring Height

• Barometric Leveling: Barometric leveling utilizes the atmospheric pressure difference between two points to determine the height difference.
• Trigonometric Heighting: Trigonometric heighting involves measuring the vertical angles from two known points to the inaccessible point and using trigonometric calculations to determine the height.

2. Methods for Measuring Distances

• Indirect Measurement: Indirect measurement techniques, such as using prisms and reflectors, are employed to measure distances to inaccessible points.
• Laser Scanning: Laser scanning technology can be used to capture detailed 3D data of inaccessible areas, allowing for accurate distance measurements.

III. Traversing with Theodolite on Surface

Traversing with a Theodolite on the surface is a common method used in mining surveying to establish a network of control points. The following steps outline the procedure for traversing with a Theodolite on the surface:

A. Definition and Purpose of Traversing

Traversing is the process of measuring angles and distances between consecutive points to establish a network of control points. It helps in accurately mapping and positioning mining features.

B. Procedure for Traversing with Theodolite on Surface

1. Setting up the Theodolite

To begin traversing with a Theodolite on the surface, the instrument must be set up correctly:

• Choose a stable and level ground for setting up the Theodolite.
• Place the Theodolite on a tripod and ensure it is properly leveled.
• Align the Theodolite with a known reference point.

2. Taking Readings and Measurements

Once the Theodolite is set up, the following readings and measurements are taken:

• Sight the first point and record the horizontal and vertical angles.
• Measure the distance between the first and second points using a tape measure or EDM.
• Rotate the Theodolite to the next point and repeat the process.

3. Calculating Coordinates and Angles

After completing the traversing measurements, the coordinates and angles of the control points can be calculated using trigonometric calculations and adjustment methods.

IV. Traversing with Theodolite Underground

Traversing with a Theodolite underground presents unique challenges and considerations due to the confined and often complex nature of underground mining environments. The following steps outline the procedure for traversing with a Theodolite underground:

A. Challenges and Considerations for Underground Traversing

Traversing with a Theodolite underground requires careful planning and consideration of the following factors:

• Limited visibility and access to points.
• Potential obstructions and hazards in the underground environment.
• Need for specialized equipment and techniques.

B. Procedure for Traversing with Theodolite Underground

1. Setting up the Theodolite in Underground Conditions

To begin traversing with a Theodolite underground, the instrument must be set up in the challenging underground conditions:

• Choose a stable and accessible location for setting up the Theodolite.
• Ensure proper lighting and visibility.
• Take necessary safety precautions.

2. Taking Readings and Measurements in Underground Conditions

Once the Theodolite is set up, the following readings and measurements are taken in the underground conditions:

• Sight the first point and record the horizontal and vertical angles.
• Measure the distance between the first and second points using a tape measure or EDM.
• Navigate through the underground environment, taking readings and measurements at each point.

3. Calculating Coordinates and Angles in Underground Conditions

After completing the traversing measurements underground, the coordinates and angles of the control points can be calculated using trigonometric calculations and adjustment methods suitable for underground conditions.

V. Checks on Closed and Open Traverses

In mining surveying, closed and open traverses are commonly used methods for establishing control networks. Checks and verifications are performed to ensure the accuracy and reliability of the traverses.

A. Definition and Purpose of Closed and Open Traverses

• Closed Traverse: A closed traverse is a network of control points where the starting and ending points are the same. It forms a closed loop.
• Open Traverse: An open traverse is a network of control points where the starting and ending points are different. It does not form a closed loop.

B. Checks and Verifications for Closed Traverses

Closed traverses undergo specific checks and verifications to ensure their accuracy and reliability:

1. Checking Closure Errors

Closure errors are checked to determine the accuracy of the closed traverse. The closure error is the difference between the measured and calculated coordinates of the starting and ending points.

2. Adjusting Traverse Measurements

If closure errors are detected, adjustments are made to the traverse measurements using various adjustment methods such as the compass rule, transit rule, or Bowditch rule.

C. Checks and Verifications for Open Traverses

Open traverses also require checks and verifications to ensure their accuracy and reliability:

1. Checking Accuracy and Reliability of Measurements

The accuracy and reliability of measurements in an open traverse are checked by comparing the measured coordinates with known control points or benchmarks.

2. Adjusting Traverse Measurements

If discrepancies are found, adjustments are made to the traverse measurements using appropriate adjustment methods.

VI. Balancing of Traverses

Balancing traverses is an important step in mining surveying to identify and correct errors in traverse measurements. The following steps outline the procedure for balancing traverses:

A. Definition and Purpose of Balancing Traverses

Balancing traverses involves identifying and correcting errors in traverse measurements to ensure the accuracy and reliability of the surveying data.

B. Procedure for Balancing Traverses

The procedure for balancing traverses includes the following steps:

1. Identifying and Correcting Errors in Traverse Measurements

• Compare the measured coordinates with known control points or benchmarks.
• Identify any discrepancies or errors in the traverse measurements.
• Determine the type and magnitude of errors.

2. Balancing Coordinates and Angles

• Apply appropriate adjustment methods to balance the traverse measurements.
• Adjust the coordinates and angles of the control points based on the identified errors.

VII. Real-world Applications and Examples

To better understand the practical applications of measurements and traversing in mining surveying, let's explore some examples:

A. Examples of Measurements and Traversing in Mining Surveying

• Determining the height of a mining pit to calculate the volume of extracted material.
• Measuring the distances between drill holes to plan the layout of explosives for blasting.
• Establishing control points for accurate mapping of underground tunnels.

B. Case Studies of Measurements and Traversing in Mining Projects

• Case Study 1: Measurement and traversing techniques used in a large-scale open-pit mining project.
• Case Study 2: Application of measurements and traversing in an underground mining operation.

VIII. Advantages and Disadvantages of Measurements and Traversing

Measurements and traversing in mining surveying offer several advantages, but they also have limitations and disadvantages:

A. Advantages of Accurate Measurements and Traversing in Mining Surveying

• Precise measurements and traversing enable accurate planning and design of mining operations.
• Establishing control networks ensures the reliable positioning of mining features.
• Checks and verifications help identify and correct errors, improving the overall accuracy of surveying data.

B. Disadvantages and Limitations of Measurements and Traversing in Mining Surveying

• Inaccessible areas or hazardous conditions may limit the accuracy and reliability of measurements.
• Traversing in underground environments can be challenging due to limited visibility and potential obstructions.
• Errors in measurements and traversing can occur, requiring adjustments and additional verification.

IX. Conclusion

In conclusion, measurements and traversing are fundamental aspects of mining surveying. Accurate measurements of height and distances, along with precise traversing using a Theodolite, are essential for planning, designing, and mapping mining operations. Checks on closed and open traverses, as well as the balancing of traverses, ensure the accuracy and reliability of surveying data. While measurements and traversing offer numerous advantages, they also have limitations and require careful consideration of the specific mining environment. By understanding the principles and procedures of measurements and traversing, mining surveyors can effectively contribute to the success of mining projects.

Summary

Measurements and traversing play a crucial role in mining surveying for planning and designing mining operations. Measurements involve determining the height and distances of points using various methods and instruments. Traversing is the process of measuring angles and distances between consecutive points to establish a network of control points. Theodolite is commonly used for traversing on the surface and underground. Checks and verifications are performed on closed and open traverses to ensure accuracy. Balancing traverses helps identify and correct errors in measurements. Measurements and traversing have advantages and limitations in mining surveying.

Analogy

Imagine you are an explorer mapping a new land. To accurately navigate and understand the terrain, you need to measure the heights of mountains, the distances between landmarks, and establish a network of control points. This information helps you create a reliable map of the land, ensuring accurate exploration and planning. Similarly, in mining surveying, measurements and traversing are essential for mapping and positioning mining features, enabling precise planning and design of mining operations.