兖石铁路房建设备中混凝土挑檐房屋达30多万平方米,占房建设备总量的28.9%,且挑出净长较大,一般是在1.5-1.8米。由于原设计是在70年代,强调低筋设计,加之施工技术较差,钢筋埋植的位值相对位移,挑檐开裂下沉现象较为普遍。从1996年至1997年的春检资料中表明:建议大修件名的有50%以上为屋面大修,其中65%为混凝土挑檐开裂下沉,或因开裂引起屋面漏雨。 Yan Shishi Railway construction equipment in the concrete roof eaves house more than 30 million square meters, accounting for 28.9% of the total construction equipment, and singled out a long net, usually 1.5-1.8 meters. As the original design was in the 1970s, emphasis was placed on the design of low-profile bars, coupled with poor construction technology and the relative displacement of bit values ​​embedded in steel bars. Cracking of the eaves was more common. From 1996 to 1997, the spring seizure data showed that over 50% of the recommended overhaul parts were roof overhaul, of which 65% were caused by cracking of concrete eaves and roof leaking due to cracking.