Influence of masonry structural building crossed by double-line parallel shield tunnel

Considering the interaction of building-soil-tunnel, the raft foundation masonry building vertical crossed by double-line parallel shield tunnel was simulated by 3D MIDAS/GTS software, and the impact of construction on the building was analyzed. The results show that: When the distance between double-line parallel shield tunnel axis and building axis was zero (L=0m), after the left-line had already passed the building, with the increase of shield tunnel distance, the settlement of the building increased. During the right-line shield tunnel excavation, the building´s foundation had differential settlement in driving direction, and it increased first and then decreased gradually to zero. The building´s maximum lateral horizontal decreased, and the maximum longitudinal displacement increased first and then decreased. The maximum first principal stress P₁ exceed the standard value which may cause some structural cracking. With the increase of L from zero, the settlement curves´ shape changed, and they tilted towards to one side of the tunnel, and the largest settlement increased first and then decrease, and the local foundation tilt increased first and then decreased. When double-line parallel shield tunnel axis and the axis coincide with the building axis, the building maximum first principal stress and maximum shear strain reached the maximum. When the double-line parallel shield tunnel was under the building, it may cause large harm to the building. When the two-lane tunnel is moving away from the building, its adverse effects on the building was decline. Finally, the safety of the building was assessed comprehensively.