Stress and Strain Sensing Device

A stress and strain sensing device comprising:

• a pillar-shaped case to be buried and installed in bedrock;
• a pressure receiving member that has two pressure receiving surfaces for sensing stress received from the bedrock and strain of the bedrock, wherein the two pressure receiving surfaces are both arranged on a common axis orthogonal to an axial direction of the case such that the two pressure receiving surfaces are exposed to an outside through an outer peripheral wall of the case and wherein the pressure receiving member is not connected with the case mechanically;
• a displacement sensor that senses the stress received from the bedrock and the strain of the bedrock based on a displacement amount between the two pressure receiving surfaces;
• a member for providing fluid tightness between the pressure receiving member and the case such that the pressure receiving member can slide with respect to the case;
• and
• a substantially ring-shaped connection member that is connected to the two pressure receiving surfaces and that elastically deforms when the two pressure receiving surfaces receive the stress, wherein
• the pressure receiving member and the connection member are formed as an integral body.