富水砂层冻结斜井内外壁受力特性实测

西安科技大学 建筑与土木工程学院,陕西 西安 710054

富水砂层; 冻结法; 斜井内外壁; 受力特性; 实测研究

In-situ measurement on stress of frozen inner and outer inclined shaft lining in water-rich sand stratum
REN Jian-xi,SUN Jie-long,ZHANG Kun,DONG Xi-hao,SONG Yong-jun

(College of Civil and Architectural Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

water-rich sand stratum; freezing method; inner and outer inclined shaft lining; pressure characteristics; in-situ measurement

DOI: 10.13800/j.cnki.xakjdxxb.2017.0603

备注

为了解决富水砂层斜井冻结法凿井的技术难题,以陕北某冻结斜井为研究对象,采用现场实测的方法,对冻结压力、冻结斜井内外壁钢筋受力、混凝土应变进行了研究,分析了冻结斜井内外壁受力特性。结果 表明:在冻结法凿井过程中,外壁受力可分为3个变化阶段,缓慢增长阶段、快速增长阶段以及平稳阶段; 内壁纵向钢筋主要承受拉应力,最大拉应力为13.8 MPa,远小于其屈服强度300 MPa,内壁处于安全状态; 内壁环向钢筋先受拉后受压,其所受最大压应力为35.06 MPa,也小于其屈服强度,进一步说明内壁处于安全状态; 内壁混凝土应变可分为受拉阶段、快速受压阶段和稳定受压阶段3个变化阶段。研究成果为指导工程实践提供了一定依据。

In order to solve the technological problems of freezing inclined shaft in the water-rich sand stratum,the paper took a freezing inclined shaft in northern Shaanxi as s research object.By using the in-situ measurement method,we measured and analyzed the pressure of freezing wall,the stress of steel bars of the inner and outer shaft,and the concrete strain and mechanical properties of shaft.The results show that the pressure of outer shaft can be divided into three stages of change: slow increase stage,rapid increase stage and stable stage.The vertical steel bars of inner shaft mainly bear tensile stress,and the maximum tensile stress is 13.8 MPa; the circular steel bars of inner shaft bear tensile stress first,then turn to compression,and the maximum tensile stress is 35.06 MPa,which is far less than the yield strength of 300 MPa.The concrete strain of inner shaft can be divided into three stages of change:under tensile stress stage,increase and stable stage under compressive stress.