钻孔应变仪体应力灵敏系数的影响因素研究

RESEARCH ON INFLUENCING FACTORS OF BODY STRESS SENSITIVITY COEFFICIENT OF BOREHOLE STRAINMETER

分别计算了水泥弹性模量、水泥层厚度、钢筒厚度、岩石弹性模量等对钻孔应变仪体应力灵敏系数的影响,得出:1)在水泥弹性模量小于某个固定值时,体应力灵敏系数随水泥弹性模量的增大而增大,大于这个值时,体应力灵敏系数又随水泥的弹性模量增大而变小;2)当水泥层厚度比N<2时,体应力灵敏系数变化剧烈,受水泥层厚度影响较大;3)体应力灵敏系数随钢筒厚度及岩石弹性模量的增大而变小。

We calculated the magnitude of the stress sensitivity coefficient of the borehole strainmeter which was impacted by modulus of cement, cement thickness, the thickness of steel tube and modulus of rock. The resuhs showed that ： 1 ） When the modulus of cement is smaller than a fixed value, the sensitivity coefficient of body stress increases with increasing of the modulus of cement. When the modulus of cement is bigger than the fixed value, the sensitivity coefficient of body stress decreases with increasing of the modulus of cement. 2） When the ratio of cement layer＇ s thickness is less than 2, the body stress sensitivity coefficient changes violently, and it was affected greatly by cement layer＇ s thickness. 3 ） The sensitivity coefficient of body stress drops with the increasing of the thickness of steel tube and modulus of rock.