测定一块岩石成岩压力的可能性

用一种超低弹性模量(约为0.01MPa)且具有光弹性的软材料铸模的自重卸荷实验证明了固体材料对它的固化压力具有“记忆”的属性。根据成岩地质体在开挖条件下实测位移场特征和用具有“记忆”性能的相似材料所做的开挖模拟实验结果分析,岩石很可能也具有这种属性。这就为测定岩石成岩压力的可能性提供了重要的理论依据。

THE POSSIBILITY OF DETERMINING ROCK RORMING PRESSURE OF A SAMPLE OF ROCK

The results of the experiment proved the first author’s supposition that when a body changes from the liquid to the slolid state there is a quontity difference of a regularity in the mechanical properties in their different depthes of it because the solidification pressure gradient is not equal to zero;and there is no elastic potential energy to change from others to in the body,in otherwords,the density of the strain energy equals zero anywhere in the body,and therefore no relaxed rebound phenomenon to occur in any lower part of the body no matter how cut off the upper part. The material used in the experiment is a soft elastic material.It is made from fusing gelatine,glycerin and water in the ratio of 3 to 5 to 12,and is of the phatoelastic property.And when a body of the material acted on by its self weight volume force,its deformation will be observed easily with the naked eye alone. The repeated experiments show that the cast mould body of the soft elastic material has a property of “memory” of its solidifacation confining pressures from the self weight volume force of the body(from the hiquid to the solid state)in a long vertical cast tube.If a confining pressure p acting on a small unit of the material is more than its salidification cofining pressure p s,the volume of the unit will be reduced;if 0≤ p≤p s,the valume will not change,and if p <0,by the first author’s inference,the volume will expand. According to the experimental results,the first author proposed“materials haveing a proerty of ‘memory’ of their solidification confining pressures”.And according to the characteristic of the displacement field caused by the open excavation,the fiest author inferred that the rock in a rock-forming geological body can also be of the property of “memory” of its rock-forming confining pressure. It is easy for us to determine the confining pressure that acts on a sample of rock and makes its volume reduse using hydraulic pressure method,so it is possible to determine rock-forming pressure p s of a sample of rock.