APPLICATION OF DOUBLE CONNECTION TRIANGLES METHOD IN VERTICAL-SHAFT CONNECTION SURVEY
双联系三角形法在竖井联系测量中的应用

Double connection triangles method in vertical-shaft connection survey is proposed. Compared with the single connection triangle method, this method not only improves the accuracy but also gives a significant increase in check conditions. Three-wire connection triangle method and double stations connection triangle method are compared with each other to analyze the application from their advantages and disvantages. Three-wire method is often used in spacious shafts because of its good stability, simple operation and conveniences. Double stations method is more time-saving and more convenient to the shaft, but it is often limited by the underground space and circumstances. So the former is more commonly used.