The invention discloses a tunnel transverse
cave-to-master
cave top brushing construction method. The tunnel transverse
cave-to-master cave top brushing construction method comprises the steps that firstly, a transverse cave is constructed to an upper step of a regulated master cave, climbing and direct top brushing are carried out from the top arc outline of the master cave to the width direction of the master cave through a small guiding cave, and a beam is erected at the joint of the transverse cave top and the master cave; secondly, a primary support is carried out on the master cave of the small guiding cave part; thirdly, a vertical support temporarily supported by the small guiding
cave in the master cave large mileage direction is dismounted, and the upper step of the master cave is excavated through expanding in the master cave large mileage direction; fourthly, a vertical support temporarily supported by the small guiding
cave in the master cave small mileage direction is dismounted, and the upper step of the master cave is excavated through expanding in the master cave small mileage direction through a
step method. The invention further discloses a tunnel transverse cave-to-master cave top brushing structure. The small guiding cave top and the master cave top of the top brushing structure are consistent in structure, the beam is erected at the joint of the transverse cave top and the master cave, and a small guiding cave temporary support is located above a master cave primary support. The top brushing excavation area is small, and the construction risk is low.