Full single layer combined bridge with four left running independent 'Y'-shaped bifurcate bridges

The invention discloses a full single layer combined bridge with four left running independent 'Y'-shaped bifurcate bridges. The full single layer combined bridge is in a combined structure which is formed by using four impendent bifurcate arch bridges and can allow multiple bridges at an intersection to be smooth. Each bifurcate arch bridge is provided with a straight arch bridge and a right turning bridge, the right turning bridge is positioned at the right side of the straight arch bridge, the right turning bridge is bifurcated with the straight arch bridge at the right turning side to form a 'Y'-shaped bifurcate bridge, and four bifurcate arch bridges form four homodromous bifurcate 'Y'-shaped bridges; and two homodromous bifurcate 'Y'-shaped bridges form a grouped bridge, and the single running sections of two groups of straight bridges of the two grouped bridges form a stereo cross structure. The full single layer combined bridge has the advantages that: the disaster degree of local geological change to the whole combined bridge is reduced; the right turning bridge can be used as a shared bridge for right turning and left turning, so that the wider ground is used as a lane merging zone to prevent traffic jam; and redundant circumambulation is avoided due to direct right turning, so that small intersections of bidirectional six lanes are fully communicated.