| Tunnel deformation joint is the most vulnerable part of waterproof position in tunnel engineering,so it is particularly important to study the waterproof performance law of tunnel deformation joint structure and put forward a new solution.The new tunnel deformation joint structure is an improved structure based on the idea of solving from the source,which has many advantages such as simple construction,convenient maintenance and adapting to more working conditions.In view of the problems of the existing tunnel deformation joint structure,such as high construction technical requirements,inconvenient maintenance in later period,and inadaptability to large deformation,this thesis proposes a new improved tunnel deformation joint structure,and carries out relevant theoretical,experimental and numerical simulation analysis.The main work completed in this thesis is as follows:（1）A new tunnel deformation joint structure is proposed.Compared with the standard structure,this new improved structure has many inherent advantages at the beginning of design,including low construction difficulty,convenient maintenance after damage,and able to bear large displacement deformation.In addition,a set of test device is designed to test the tunnel deformation joint structure,which can accurately measure the seepage water amount and seepage pressure of the specimen under a variety of working conditions,which can meet the requirements of experimental research.（2）Under displacement loading,for 30 mm joint width,the anti-seepage performance of the improved structure specimen is 59% better than that of the standard structure,and there is little difference in fatigue resistance between the two specimens,but the overall fatigue resistance of the improved structure specimen is 13% better than that of the standard structure.For the joint width of 25 mm,the anti-seepage performance of the improved structure is 85% better than that of the standard structure,and the fatigue resistance of the improved structure is 14% less than that of the standard structure,but the overall fatigue resistance of the improved structure is 11% better than that of the standard structure.For the20 mm joint width,the anti-seepage performance of the improved structure specimen is 120%better than that of the standard structure,and the fatigue resistance of the improved structure specimen is 35% less,but the overall fatigue resistance of the improved structure specimen is 12% better than that of the standard structure.Under loading,the average impermeability of the three joint widths is slightly worse than that of the standard specimen.However,the fatigue resistance of the modified specimen is increased by 11% on average compared with that of the standard specimen..（3）The waterproof capacity of the standard structure was improved by the two flexible improvement methods,the overall average increase of waterproof roll material was 6%,and the overall average increase of waterproof coating was 3%,but the waterproof capacity of waterproof roll material and waterproof coating was limited to the low displacement difference level and low fatigue loading times.Waterproof roll has good adaptability to narrow deformation joint width;Waterproof coating can only have a good waterproof effect on the tiny cracks of static buildings.（4）For both kinds of specimens,the ultimate value of bearing capacity of specimens with 25 mm deformation joint width is the largest,and the ultimate displacement of specimens with improved structure is more than 5mm than that of standard specimens.The shear strength of the standard structure specimens increases first and then decreases,while the shear strength of the improved structure specimens decreases first and then increases,and is about 46% better than that of the standard specimens under large loads.The standard modification is sensitive to the effect of slit width,while the modified specimen can adapt to various slit widths.The failure modes of each component of the two types of structures analyzed by ABAQUS finite element software are the same as those in the test.The gap between simulation and test under three deformation joint widths is no more than 15%. |
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