Lecture 08 Traverse surveying скачать в хорошем качестве

Lecture 08 Traverse surveying

This lecture provides a detailed explanation of traverse surveying, a crucial topic in civil engineering (0:06). Here's a breakdown of the key concepts covered: Definition of Traverse (1:06): A traverse is defined as a series of connected lines whose lengths and directions are measured in the field. Quadrant System (1:42): The video explains the quadrant system used in traverse surveying, noting that it's a clockwise system opposite to the normal geometric quadrant system. Latitude and Departure: The projection of a line on the North-South axis is called latitude (2:43), and on the East-West axis is called departure (2:55). Signs in Quadrants: The video details the positive and negative signs for latitude and departure in each of the four quadrants (3:08-4:30). Formulas: Latitude is calculated as L cos θ and Departure as L sin θ (6:33). Calculations for Latitude and Departure (7:44): The lecture emphasizes that only the fore bearing of a line is used for these calculations. It also highlights that when using whole circle bearing, the nature (sign) of latitude and departure is automatically taken care of by the trigonometric functions, eliminating the need for manual sign assignment (10:21). Closed Traverse (11:12): For a closed traverse, the sum of latitudes and the sum of departures should ideally be zero (16:07-17:12). The video illustrates this with a diagram and explanations. Closing Error (17:26): When a traverse does not close at its starting point, a closing error occurs. In such cases, the summation of latitudes and departures will not be zero. Magnitude of Closing Error: The magnitude of the closing error (E) is calculated using the formula: E = √(EL² + ED²), where EL is the total error in latitude and ED is the total error in departure (20:40). Direction of Closing Error: The direction is given by tan⁻¹(ED / EL) (21:17). Methods to Correct Closing Error (21:43): 1. Bowditch Rule (21:53): This method is applied when both linear and angular measurements are taken with equal precision. Error in linear measurement is proportional to √L (22:56). Error in angular measurement is proportional to 1/√L (23:03). Correction for latitude and departure are distributed based on the ratio of line lengths (24:22). 2. Transit Rule (25:19): This method is used when angular measurements are more precise than linear measurements (25:40). The video concludes with a quick recap of all the major topics discussed (26:57) and mentions that the next lecture will cover practice questions from various exams.