分布式光纤在基桩静载荷试验中的应用  

Application of BOTDR Sensor in Pile on-Site Loading Test

作　　者：宋建学[1] 白翔宇[2] 任慧志 

机构地区：[1]郑州大学土木工程学院,郑州450002 [2]新乡学院建筑工程系,河南新乡453003 [3]河南省朝阳建筑设计有限公司,郑州450008

出　　处：《河南大学学报（自然科学版）》2011年第4期429-432,共4页Journal of Henan University:Natural Science

摘　　要：针对郑州会展宾馆7根试桩(桩长60 m和67 m两种)的静载荷试验,分别采用分布式光纤BOTDR和振弦式钢筋应力计两种方案对各级载荷下的桩身应变进行监测.结果表明,两种方案得到的桩身轴力大小及分布均十分相似,但前者反映的信息更加丰富,后者的结果会掩盖桩身轴力的精细变化.根据分布式光纤的技术特点,建议由桩头实测应变反演得到桩身混凝土弹性模量.BOTDR技术使得确定桩端下刺入量成为可能,由该方案得到的轴力结果具有较高的可靠性.On-site loading tests are carried out on seven pile specimens in Zhengzhou,with the length of pile being 60 m and 67 m.The Brillouin optical time-domain reflectometer（BOTDR） sensors and vibrating wire sensors are employed to obtain the strains of piles corresponding to each step of loading.The results indicate that the profiles of axial force in pile from the two systems are very close to each other,either in shape or in magnitude.However,the former manifests that the piles are working in bottom bearing and friction mechanism,and the later shows that they are working only in friction mood.It is advised that the elastic modulus of concrete be determined by the inversion calculation based on obtained strains.The BOTDR system facilitates the determination of penetrating pile into the bottom soil,and the conclusion from BOTDR is more reliable.

关 键 词：土木建筑工程设计 分布式光纤 BOTDR静载荷试验 桩 

分 类 号：TU317.3[建筑科学—结构工程]