Monitoring While Drilling And Quality Evaluation Of Rock And Soil

The development and utilization of underground space has become an important way for urban sustainable development.Shield construction is an important method for underground space development.The evaluation method of rock and soil quality for shield construction is not mature,which affects the design and construction of underground space.The principle of in-situ drilling while monitoring is similar to that of shield construction.Exploring the quality evaluation method of rock and soil based on the monitoring while drilling is expected to be an effective way to solve the major geotechnical problems encountered in shield tunnel construction.This paper focuses on the scientific and technological problems such as the improvement of the monitoring instrument while drilling,the intelligent data acquisition and transmission,the standardization processing of the monitoring data while drilling,the quality of rock and soil and the evaluation of its mechanical properties.The main achievements are as follows:The LWD monitoring equipment for underground space shield construction has been improved,and intelligent acquisition and transmission of data has been realized.The technology while drilling is an emerging technology in the evaluation of rock mass and its mechanical properties.By monitoring the drilling depth,drilling speed,rotational speed,oil pressure and torsion pressure in the whole process of drilling,the geology is Analysis of body characteristics will be more realistic.On the basis of predecessors,a set of drilling-while monitoring equipment for underground space shield construction adapted to weak strata has been improved through experiments,and a new torsional pressure sensor and wireless transmission system have been added,which can continuously and continuously monitor drilling.The process realizes intelligent collection and transmission of data.A standardized processing method for monitoring data while drilling is proposed.Using the hydraulic drilling rig commonly used in engineering geology as a platform,the data acquisition and processing work was carried out in Xi'an and Yan'an areas using improved drilling while monitoring equipment.The original time series data collected while drilling is subjected to standardization processing of the while-drilling monitoring data,and the analysis and analysis standards for the monitoring data while drilling in soft strata are summarized.Pure-drilling data obtained from the standardization of the monitoring data while drilling,and analyzing the data to establish the relationship between the monitoring parameters while drilling and the lithology of the formation.The relationship between the standardized data while drilling and the mechanical and physical parameters of rock and soil was established.Through a series of simultaneous drilling monitoring data and test results data comparison analysis,as well as electronic scanning test and mineral analysis test,the relationship between the monitoring parameters while drilling and the lithology of the formation is analyzed from the microscopic point of view.Based on the regression analysis of the parameters while drilling along the same stratum,the geotechnical classification standard based on the drilling parameters for underground space shield construction was preliminarily constructed,and the drilling while logging and logging data were used to verify the drilling while monitoring.The correctness of the results.The research shows that the monitoring data while drilling well reflects the characteristics of geotechnical and physical parameters,and initially establishes the geotechnical classification standard based on the monitoring while drilling,which provides the division and evaluation of rock mass quality for underground space shield construction.The scientific basis.