Research on Dynamic Response and Construction Safety Countermeasures of an Adjacent Existing Line Foundation under the Influence of a New Railway Line

The excavation of a new high-speed railway causes the side slope adjacent to existing line foundation become airborne, and excessive dynamic deformation or cumulative caused by load trains will affect normal service subgrade, even leading its instability. To date, there are no relevant experimental data regarding this, is also lack corresponding specifications. only available numerical simulation research results need be verified in practice. Therefore, this study relies on Shanghai–Nanjing intercity construction project Beijing–Shanghai carry out subgrade response test ensure safe operation line. obtained vibration displacement, frequency, acceleration, other parameters three stages: excavation, pile formation, filling. From results: During period, vertical surface displacement acceleration have certain attenuation along depth direction. In stage generated largest. amplitude reaches 1.9 mm, horizontal 0.15 mm. frequency roadbed under action train concentrated range 0–50 Hz, energy at peak value relatively large, which reflects train, mainly 20–40 Hz. These show that maximum appears stage, is, most dangerous subgrade. each parameter important they reflect performance establish index control standard, can used as for stability monitoring. state provides support reasonable opening skylight protection slope. Taking into account impact piling vibration, technical measures such static pressure, jumping construction, setting up stress relief holes adopted. engineering theoretical significance guiding