The Qinghai-Tibet Railway has been operating safely for 16 years in the permafrost zone and the railroad subgrade is generally stable by adopting the cooling roadbed techniques. However, settlement caused by the degradation of subgrade permafrost in the embankment-bridge transition sections (EBTS) is one of the most representative and severe distresses. A field survey on 440 bridges (including 880 EBTSs) was carried out employing terrestrial laser scanning and ground-penetrating radar for comprehensively assessing all EBTSs in the permafrost zone. The results show that the types of distresses of EBTSs were differential settlement, upheaval mounds of the protection-cone slopes, subsidence of the protection-cone slopes, surface cracks of the protection cones and longitudinal and transverse dislocation of the wing walls. The occurrence rates of these distresses were 78.93, 3.47, 11.56, 3.36, 21.18 and 4.56%, respectively. The most serious problem was differential settlement, and the average differential settlement amount (ADSA) was 15.3 cm. Furthermore, the relationships between differential settlement and 11 influencing factors were examined. The results indicate that ADSA is greater on the northern side of a bridge than on the southern side and on the sunny slope than on the shady slope. It is also greater in the high-temperature permafrost region than in the low-temperature permafrost region and in the high-ice content area than in the low-ice content area. The EBTSs are more influenced by ice content than by ground temperature. The ADSA increases when the embankment height increases, the particle size of subgrade soil decreases and the surface vegetation cover decreases.

青藏铁路在多年冻土区已安全运行16年，采用冷却路基技术，路基总体稳定。然而，路堤-桥梁过渡段（EBTS）路基多年冻土退化引起的沉降是最具代表性和最严重的病害之一。采用地面激光扫描和探地雷达对440座桥梁（其中880座EBTS）进行了实地调查，对多年冻土区所有EBTS进行了综合评估。结果表明，EBTS的病害类型为不均匀沉降、防护锥边坡隆起、防护锥边坡沉降、防护锥表面裂缝和翼墙纵横错位。这些困扰的发生率分别为78.93%、3.47%、11.56%、3.36%、21.18%和4.56%。最严重的问题是不均匀沉降，平均不均匀沉降量（ADSA）为15.3厘米。此外，还考察了差异沉降与11个影响因素之间的关系。结果表明，桥梁北侧ADSA大于南侧，阳坡大于阴坡。高温多年冻土区大于低温多年冻土区，高冰含量区大于低冰含量区。EBTS 受冰含量的影响大于地温的影响。ADSA随着路堤高度的增加而增加，