基于3D打印的复杂裂隙岩体模型制备试验研究

Experimental research on model preparation of highly fractured rock mass based on 3D printing

为解决复杂裂隙岩体物理模型的制备难题,在系统梳理现有裂隙岩体3D打印制备方法的基础上,提出基于3D打印的复杂裂隙岩体模型制备方法,通过溶解试验筛选出可溶性3D打印材料,使用可溶性3D打印材料制备出包含裂隙网络的复杂裂隙岩体模型,通过单轴压缩实验室试验和数值模拟试验验证复杂裂隙岩体模型的力学性质。结果表明,使用可溶性3D打印材料先行打印裂隙网络实体模型,待浇筑砂浆并养护后,再使用溶剂将裂隙材料溶解,可制备出性能优良的复杂裂隙岩体模型。改性PVA材料溶解性能优异,在浇筑砂浆条件下仍可快速溶解,形成的溶解物可作为裂隙填充材料,并具有黏结性,使复杂裂隙岩体不发生解体,适合用于制作复杂裂隙岩体模型。基于3D打印的复杂裂隙岩体制备方法有两大突出优势:与3DP直接制备方法相比,使用常规砂浆作为模型主体材料,性质可调,模型仿真性能好;与FDM间接制备方法相比,使用可溶性3D打印材料打印裂隙网络实体模型,裂隙实体可溶解,消除了裂隙材料对模型力学性质的影响。基于3D打印的复杂裂隙岩体模型制备方法可以制备主体材料为常规砂浆、包含裂隙网络的复杂裂隙岩体模型,裂隙隙宽可小至0.4 mm,并且裂隙具有弱黏结性,可广泛用于开展复杂裂隙岩体的物理模拟试验,从而将裂隙岩体的物理模拟能力扩展至复杂裂隙岩体。

In order to solve the problem of the physical model preparation of highly fractured rock mass,a preparation method for physical model of highly fractured rock mass based on 3D printing was proposed by systematically reviewing the existing 3D printing preparation methods for fractured rock mass.The soluble 3D printing materials were screened out through the dissolution test.The physical models of highly fractured rock mass contained a fracture network were prepared using the soluble 3D printing materials,and the mechanical properties of the highly fractured rock mass model were verified by uniaxial compression laboratory test and numerical simulation test.The results show that the proposed method can generate physical models of highly fractured rock mass with excellent performance by first printing the physical model of fracture network with soluble 3D printing materials,next pouring the mortar and curing,and then dissolving the fracture material with solvent.The modified PVA material has excellent solubility,which can dissolve quickly under the conditions of pouring mortar,and the dissolved material can be used as filler for fractures.The dissolved material can prevent the disintegration of the highly fractured rock mass model because of the cohesiveness.Therefore,the modified PVA material is suitable for preparing physical models of highly fractured rock mass.The preparation method of highly fractured rock mass based on 3D printing has two outstanding advantages.Compared with the direct preparation method by 3DP(three dimensional printing),the physical models have good simulation performance because of the use of conventional mortar as the main material,which has adjustable properties.Compared with the indirect preparation method by FDM(fused deposition modelling),the influence of fracture material on the mechanical properties of the physical model is eliminated by using soluble 3D printing materials to print the fracture network.The proposed method based on 3D printing can prepare physical models of highly fractured rock mass with conventional mortar as the main material and containing a fracture network,in which the width of the fracture can be as small as 0.4 mm and the fractures have weak cohesion.The physical models can be widely used for physical simulation experiments on highly fractured rock mass,thereby expanding the physical simulation capabilities of fractured rock mass to highly fractured rock mass.