Study on the estimation of lateral breakthrough error in horizontal control survey of super long tunnel
For the super long tunnel with the opposite excavation of more than 20 km,the construction environment inside the tunnel is complex,and there are few comprehensive analysis cases of the factors affecting the lateral breakthrough error inside and outside the tunnel.There are also no relevant standards and specifications for the control survey of super long tunnel,making it difficult to control the lateral weaving in the tunnel measurement.In order to predict the lateral breakthrough error for the construction of super long tunnel,the sources of lateral breakthrough error were analyzed,and the influence of control survey outside and inside the tunnel on lateral breakthrough error was studied.The influence values of GNSS outside the tunnel,angle measurement error,distance measurement error,etc.,on lateral breakthrough were estimated,and simulation calculation experiments inside the tunnel were designed,taking into account factors such as alignment error and observation error.Under the conditions of different angle measurement accuracy and different traverse lengths,the mean square error values of lateral breakthrough for different tunnel lengths within the range of 20～30 km were derived and simulated.The results show that improving the accuracy of angle measurement has a significant effect on the gain of lateral breakthrough accuracy,and the simulation results are accurate and reliable.Taking a 2 km tunnel length as the dividing interval,recommended values for the mean square error of lateral breakthrough outside and inside the super long railway tunnel are obtained.
super long tunnellateral breakthroughcontrol surveyobservation errorerror estimationsimulation calculation
万方数据
维普
