Up to now there is no specification about the allowance of lateral breakthrough error for super long tunnel from 20 km to 50 km. On the basis of the design of GPS networks located outside and inside tunnel traverse ne...Up to now there is no specification about the allowance of lateral breakthrough error for super long tunnel from 20 km to 50 km. On the basis of the design of GPS networks located outside and inside tunnel traverse network, we propose a method for calculating the influence value caused by control surveying errors. Through a lot of simulative calculations and combination with piercing practice of super tunnels in Wan Jiazai Project, Shanxi province, we present an allowance table of lateral breakthrough error for super long tunnels from 20 km to 50 km.展开更多
With the development of new materials and ultra-precision processing technology, the sizes of mea- sured objects increase, and the requirements for machining accuracy and surface quality become more exacting. The trad...With the development of new materials and ultra-precision processing technology, the sizes of mea- sured objects increase, and the requirements for machining accuracy and surface quality become more exacting. The traditional measurement method based on reference datum is inadequate for measuring a high-precision object when the quality of the reference datum is approximately within the same order as that of the object. Self-referenced measurement techniques provide an effective means when the direct reference-based method cannot satisfy the required measurement or calibration accuracy. This paper discusses the reconstruction algorithms for self-referenced measurement and connects lateral shearing interferometry and multi-probe error separation. In lateral shearing interferometry, the reconstruction algorithms are generally categorized into modal or zonal methods. The multi-probe error separation techniques for straightness measurement are broadly divided into two-point and three-point methods. The common features of the lateral sheafing interferometry method and the multi-probe error separation method are identified. We conclude that the reconstruction principle in lateral shearing interferometry is similar to the two-point method in error separation on the condition that no yaw error exists. This similarity may provide a basis or inspiration for the development of both classes of methods.展开更多
文摘Up to now there is no specification about the allowance of lateral breakthrough error for super long tunnel from 20 km to 50 km. On the basis of the design of GPS networks located outside and inside tunnel traverse network, we propose a method for calculating the influence value caused by control surveying errors. Through a lot of simulative calculations and combination with piercing practice of super tunnels in Wan Jiazai Project, Shanxi province, we present an allowance table of lateral breakthrough error for super long tunnels from 20 km to 50 km.
文摘With the development of new materials and ultra-precision processing technology, the sizes of mea- sured objects increase, and the requirements for machining accuracy and surface quality become more exacting. The traditional measurement method based on reference datum is inadequate for measuring a high-precision object when the quality of the reference datum is approximately within the same order as that of the object. Self-referenced measurement techniques provide an effective means when the direct reference-based method cannot satisfy the required measurement or calibration accuracy. This paper discusses the reconstruction algorithms for self-referenced measurement and connects lateral shearing interferometry and multi-probe error separation. In lateral shearing interferometry, the reconstruction algorithms are generally categorized into modal or zonal methods. The multi-probe error separation techniques for straightness measurement are broadly divided into two-point and three-point methods. The common features of the lateral sheafing interferometry method and the multi-probe error separation method are identified. We conclude that the reconstruction principle in lateral shearing interferometry is similar to the two-point method in error separation on the condition that no yaw error exists. This similarity may provide a basis or inspiration for the development of both classes of methods.
