Numerical Simulation Study on Expansive Force of Lining for Tunnel in Expansive Soil
|School||Southwest Jiaotong University|
|Course||Bridge and Tunnel Engineering|
|Keywords||Expansive soils Tunnel Structural internal force Numerical Simulation|
Expansive soil is a multi- fractured and has significant swelling and shrinkage of the geological body . Expansive geotechnical repeated water swelling , dehydration contraction, causing very serious consequences on the tunnel project . Must therefore be obtained by studying the mechanism of action of the tunnel through the expansive soil , as well as to swelling stress redistribution law , to identify the appropriate countermeasures , thus guiding the design and construction of the expansion of the structure of the soil tunnel . In this paper, the Ministry of Railways Design Institute project \First introduced the expansion and contraction of the expansive soil causes and mechanism of expansion of soil tunnel computing method ; introduces the basic features of the expansive soil surrounding rock , and expansive soil tunnel of common diseases and preventive measures . And finite element numerical simulation analysis of tunnel excavation , surrounded by expansive soil water swelling obtained different case LINING and the surface displacement dong weeks displacement distribution of the tunnel lining , BOLT , come to the following Conclusion: (1) tunnel lINING depth, expansion rate and expansion ring thickness . Expansion factors LINING is very significant , and the depth of small factors . (2) For the purposes of a an anchor for expansion around the maximum axial force anchor and lining junction , the anchor bolt axial force along the axial direction from the inside outward descending . Bolt axial force of arch back at the largest dome at the bolt axial force minimum. (3) a linear relationship between tension and expansion rate of the anchor . In the case of certain of the expansion ratio , the expansion ring thickness has little influence on the maximum axial force on the anchor rod . ( 4 ) is much greater than the depth of the thickness and the expansion rate of expansion loops lining deformation . The expansion of the expansion ring ( 5) around the tunnel , up the dome surface uplift; increases with the depth of the depth of the dome above the surface displacement increases . (6) the expansion rate of the tunnel structure , the minimum The expansion loops thickness , followed by the depth of tunnel structure .