爆破成井装药结构与中心孔药量的模拟与实践

为研究小断面急倾斜天井采用VCR法一次爆破成井的中心孔药量问题,采用ANSYS/LS-DYNA对成井过程进行了数值模拟。根据C·W利文斯顿球状药包理论,采用5孔布置、单孔中心掏槽、同分层中心孔与边孔不等高装药模拟成井过程。通过观察爆炸作用下岩石塑性应变场的变化,确定该方法能够很好地解决岩石夹制性问题。进而,改变中心孔药量进行多组模拟,发现不同中心孔药量与井壁上不同位置的单元应力对岩石抗拉强度的二阶矩的值呈非线性关系,并由此总结出中心孔药量的确定方法。工程实例验证了采用不等高装药与使用合理的药量能够达到理想的成井效果。

Simulation and practice of charge structure and center hole charge quantity of raise-forming blasting

In order to study the center hole charge quantity of VCR(Vertical Crater Retreat)method of sharp inclined raise blasting with a small section,ANSYS/LS-DYNA software was used to simulate the raise-forming process.According to the theory of C·W Livingston's spherical charge,5-holes arrangement,single-hole center cutting,differ-height charge of the same stratification center hole and side holes were used to simulate the raise-forming process.By observing the plastic strain field of the rock under the action of the explosion,the method was determined to be used to solve the rock clamping problem.Many simulations were conducted by changing the center hole charge quantity.It showed that different center hole charge quantity and the stress of element at different location on the borehole wall had nonlinear relationship with the second moment of the tensile strength of the rock.Therefore the method of determining the center hole charge quantity was summarized.Engineering examples proved that the use of differ-height charge and reasonable charge quantity could achieve ideal raise-forming effect.