香港元朗地区大理石的力学性质

The mechanical properties of Yuen Long marbles of Hong Kong

本文讨论香港元朗地区大理石的力学性质，一般的说，颗粒小致密的黑色大理石超声波速度高、抗压强度大且具有脆性特征。其Ｐ波和Ｓ波的速度分别为６．２２～６．５０ｋｍ／ｓ和３．２５～３．６４ｋｍ／ｓ，其单轴抗压强度为８８～１６６ＭＰａ。而颗粒较粗的白色或灰色大理石超声波速度变化很大，单轴抗压强度小且具有塑性特征。其Ｐ波和Ｓ波速度分别为３．３５～６．４５ｋｍ／ｓ和２．２４～３．１６ｋｍ／ｓ，其抗压强度为５２～６３ＭＰａ。Ｐ波速度和抗压强度与微裂隙密度和微裂隙长度成反比。大理石的内部微观结构，如裂隙、颗粒大小是影响其力学性质的主要因素。

The paper discusses the mechanical properties of Yuen Long marbles of Hong Kong. Generally, the fine grain dark marbles are of brittle features. Their ultrasonic wave speeds and peak strength are high. Their P wave speed and S wave speed are 6. 22 to 6. 50km/s and 3. 25 to 3. 64 km/s respectively. Their peak strengths are 88 to 166 MPa. However, the coarse grain white and grey marble are of ductile features. Their ultrasonic wave speeds are low and unstable. Their peak strength is low. Their P wave speed and S wave speed are 3.35 to 6.45 km/s and 2. 24 to 3. 16 km/s respectively. Their peak strengths are 52 to 63 MPa. P wave speeds and peak strength decrease with the crack length and crack density. The micro-structure , such as crack , and grain scale are the main factors that affect the mechanical properties of the marbles.