| With the rapid development of transportation engineering and inter-basin water conveyance engineering,more and more long,large and deep tunnels are being and will be built all over the world.Tunnel boring machine(TBM)method is the preferred method in tunnel construction.Because the TBM method has many advantages in safety,environmental protection and high efficiency.However,TBM has poor adaptability to the excavated rock mass.The insufficient and untimely perception of rock mass information and the unclear rock-machine interaction relationship are the important factors restricting the safe and efficient tunneling of a TBM.Based on the development of the key technology of rock mass information perception,the present study has carried out a large number of laboratory tests and in situ tests to deal with the difficulty of fast perception of rock mass information in TBM tunneling and the unclear mutual-feed relationship between rock-machine interaction.In addition,a systematic research on rock-machine interaction has been carried out.The main research contents and results of the present study are as follows:(1)Two sets of technologies for the fast perception of rock mass information during TBM tunneling are developed independently,namely rock mass in-situ indentation testing technology and fast collection technology of rock muck information,respectively.The corresponding in-situ testing methods and testing processes are proposed.The empirical relationship between rock uniaxial compressive strength and indentation indices is established through a large number of indentation tests.The fast perception of rock mass information during TBM tunneling is realized.In terms of the morphological characterization of rock muck,3D characterization of muck morphology is realized using 2D morphological parameters based on 3D scanning technology and image analysis technology.It overcomes the problems of traditional perception methods:inaccurate,incomplete and unfast measurement of rock muck information.(2)In order to verify the applicability and reliability of the developed technologies,a large number of uniaxial compression tests,point load strength tests and rock mass in-situ indentation tests have been carried out based on the ABH project.The conversion relationship between the uniaxial compressive strength(UCS)of rock and corrected point load strength is established,which forms a basic database of rock information.The influence of indentater tip diameter on in-situ indentation test results is studied.And qualitative and quantitative characterization methods of rock mass information based on in-situ indentation test are proposed.The correlation between various indentation indices is analyzed.Finally,the rock strength conversion relationship based on in-situ indentation indices is established.(3)Aiming at the insufficient and untimely perception of rock muck information in traditional methods,the database of TBM rock muck image is built.With the use of digital image processing,an automatic extraction method for 3D rock muck information is developed.The fast peception method of rock mass information(strength and integrity)is proposed using rock muck information.The mutual feedback relationship between rock mass and rock muck is realized.On the one hand,the size of rock blocks produced during TBM tunneling decreases with the increase of rock UCS.At the same time,the shape of these blocks is close to circular.On the other hand,the blocks generally have small sizes when the rock mass integrity is good.However,when there are many joints or fractures in the excavated rock mass,the block size shows a large floating range.And the flat planes can be frequently found in these blocks.(4)Based on the rock mass information obtained by the abovementioned two sets of fast perception technologies and the operating parameters recorded by TBM itself,the linear correlations between the seven TBM performance parameters(including TBM total thrust,cutter head speed,cutter head torque,penetration,rotation speed,field penetration index and torque penetration index)are analyzed.The field penetration index is finally selected as the representative parameter of TBM performance.The corresponding relationships between TBM performance parameters and rock mass information are deeply studied.Based on the in-situ indentation indices and rock muck image information,the rock-machine interaction mutual feedback relationship is established.The fast perception of rock-machine interaction information in TBM tunneling is realized. |
