Precise characterization of the mechanical properties of gelatin, a classic analog of the elastic crust, is necessary for scaling the mechanical models of the Earth's crust behavior in laboratory experiments. Here we reassess how to accurately calculate the Young modulus (E) of gelatin contained in experimental tanks. By means of dedicated analog experiments and finite element simulations, we estimate the bias introduced by using equations appropriate for a half-space to interpret the subsidence due to a cylindrical surface load applied on the gelatin. In the case of a standard experimental setup with gelatin adhering to the tank wall, we find E is overestimated by at least 5% for a box with lateral size smaller than 20 times the cylinder diameter. In addition, we deduce a correction factor to be applied when using an analytical formula. We confirm that measuring the shear velocity leads to accurate estimates for the rigidity of gelatin. We also propose a new method for in situ Young's modulus estimation, relying on the length of air-filled propagating crack. Indeed, for a given injected volume, this length depends only on the density contrast between air and gelatin and on the Young's modulus of the gelatin. The fracture toughness of the gelatin is estimated independently. Direct comparison between fracture toughness and Young's modulus shows that for a given Young's modulus, salted gelatin has a higher fracture toughness than unsalted gelatin.

明胶的机械特性的精确表征是弹性地壳的经典类似物，对于在实验室实验中缩放地壳行为的机械模型是必需的。在这里，我们重新评估如何准确计算实验罐中所含明胶的杨氏模量（E）。通过专用的模拟实验和有限元模拟，我们通过使用适用于半空间的方程式来解释由明胶上施加的圆柱表面载荷引起的沉降来估计偏见。在明胶附着在罐壁上的标准实验装置中，对于横向尺寸小于圆柱直径20倍的盒子，我们发现E高估了至少5％。此外，我们推导了使用解析公式时要应用的校正因子。我们确认，测量剪切速度可导致对明胶刚度的准确估算。我们还提出了一种新方法，该方法依赖于空气中传播的裂纹的长度来进行原位杨氏模量估计。实际上，对于给定的注射量，该长度仅取决于空气和明胶之间的密度对比以及明胶的杨氏模量。明胶的断裂韧性是独立估计的。断裂韧度和杨氏模量之间的直接比较表明，对于给定的杨氏模量，盐明胶的断裂韧度要高于未盐化的明胶。实际上，对于给定的注射量，该长度仅取决于空气和明胶之间的密度对比以及明胶的杨氏模量。明胶的断裂韧性是独立估计的。断裂韧度和杨氏模量之间的直接比较表明，对于给定的杨氏模量，盐明胶的断裂韧度要高于未盐化的明胶。实际上，对于给定的注射量，该长度仅取决于空气和明胶之间的密度对比以及明胶的杨氏模量。明胶的断裂韧性是独立估计的。断裂韧度和杨氏模量之间的直接比较表明，对于给定的杨氏模量，盐明胶的断裂韧度要高于未盐化的明胶。