-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
0 parents
commit d32a376
Showing
2 changed files
with
44 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,19 @@ | ||
function sigma=tunnel_breakthrough_error(n,s,sigma_angle) | ||
% The standard displacement error (sigma) of a geodetic station in tunneling in a | ||
% direction normal to the axis of the tunnel (lateral error). This error describes tunnel | ||
% breakthrough error (offset), and can be used in tunnel geodetic network pre-analysis. | ||
% Vectorized. | ||
% Version: 13 Jun 22 | ||
% Input: n - the number of the traverse legs | ||
% s - the length of the open tunnel traverse [meter] | ||
% sigma_angle- the standard deviation (uncertainty) of angle measurements [radians] | ||
% Output: sigma - standard error (sigma) of a geodetic station in the tunnel [meter] | ||
% Reference: Chrzanowski, A., 1981. Optimization of the breakthrough accuracy in tunnelling surveys. Canadian Surveyor 35 (1), 5 – 16. | ||
% Keywords: tunneling, surveying, standard accuracy, breakthrough error | ||
% | ||
% Copyright (c) 2022, Matej Varga | ||
% All rights reserved. | ||
% Email: [email protected] | ||
sigma = n.*(n+1).*(2.*n+1)./6.*s.^2.*sigma_angle.^2; | ||
|
||
end |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,25 @@ | ||
clear;clc;close all | ||
|
||
n= [0:20]; % number of stations | ||
s= 50; % leg distances between geodetic marks in a tunnel_breakthrough_error | ||
sigma_angle = 10; % the standard deviation for the angles measurement in arc seconds | ||
|
||
|
||
% | ||
sigma_angle = sigma_angle/3600*pi/180; % convert angle units to radians | ||
|
||
sigma_breakthrough=tunnel_breakthrough_error(n,s,sigma_angle); | ||
|
||
figure | ||
plot(n,sigma_breakthrough*1000); | ||
grid on; | ||
xlabel('Number of stations'); | ||
ylabel('Lateral displacement error [mm]'); | ||
|
||
figure | ||
plot(n*s,sigma_breakthrough*1000); | ||
grid on; | ||
xlabel('Traverse length [meter]'); | ||
ylabel('Lateral displacement error [mm]'); | ||
|
||
|