Research On Earthquake Response Laws And Prevention Measures Of Comprehensive Pipe Corridors Across Ground Fractures

In the process of construction and use of utility tunnel,there are many problems to be solved.For example,the presence of ground fissures will cause vertical settlement differences between the upper and lower walls,thus make the pipe corridors unevenly stressed.In addition,the earthquake will make the utility tunnel and the internal damaged and affect its service life.In this paper,the seismic response law of utility tunnel across the ground fissures was studied,which provides a reliable basis for the seismic research of the utility tunnel in the ground fissure areas,and further promotes the research and development process.In this paper,this research was mainly carried out by shaking table experiments and simulation calculations.Among them,the seismic response law of the utility tunnel was studied when the intersection angle between the local crack and the comprehensive pipe corridor were 30 ° and60 ° respectively.The ABAQUS software was used to simulate the response differences of various monitoring indicators of the utility tunnel when the influencing factors changed,as well as the verification of anti-seismic measures.The main results are as follows:(1)By comparing the experimental results of the two sets of shaking tables,it can be seen that when the intersection angle between the structure and the ground fissures changes from 30 ° to 60 °,the position of the maximum value of the acceleration amplification factor is still on the upper wall,but the range of acceleration amplification factor increases.That is,the maximum value of the acceleration amplification factor becomes larger and the minimum value becomes smaller.The contact pressure between the utility tunnel and the soil decreases as the intersection angle becomes larger,but the contact pressure at the bottom of the utility tunnel is always smaller than the side wall.The strain values decrease with the increase of the intersection angle.In addition,the change law of each strain value from the upper to the lower wall is more consistent than when the intersection angle is 30 °.(2)Using the ABAQUS software,by comparing the response differences of various indicators when the influencing factors such as the type of seismic wave,the intensity level of the seismic wave,the intersection angle of the utility tunnel and ground fissures variation changes,result show that the most obvious effect on the seismic response law of the utility tunnel is the earthquake intensity level.When the acceleration peak changes from 0.1g to 0.3g,the peak increase rate of stress and horizontal acceleration exceeds 100%.The intersection angle between the utility tunnel and the ground fissure ranked second.With the increase of the intersection angle,the horizontal displacement peaks and stress peaks show a decreasing trend;the type of seismic wave has the least impact.The seismic response of each factor was the strongest when EL wave was applied,followed by TAFT wave,and the seismic response was the least when Xi ’an artificial wave was applied.(3)Finally,according to the above results,seismic measures are proposed,which are mainly divided into two categories.the ground fissure effect is strong or weak.When the ground fissure is strong,the measures are: setting up seismic joints and strengthening structures;when the ground fissure function is weak,measures are: setting shock-absorbing layer and foundation treatment.Through ABAQUS verification,we know that the earthquake resistance effect of the two measures of setting seismic joint and foundation treatment is more obvious.