New Device to Measure Soil, Rock Strength Wins WIPO Award.

• Author: Omar, Husaini
• Position: H-Ometer - World Intellectual Property Organization - Brief Article

The H-Ometer, granted the World Intellectual Property Organization's (WIPO) annual gold medal award for best invention by a national from a developing country, is a new strength-measuring device developed by a group of researchers at the Mountainous Terrain Development Research Centre, Faculty of Engineering, Universiti Putra Malaysia. It has been developed to measure the indirect tensile strength of hard soil and weak rock. The H-Ometer is a cylindrical probe with an expandable flexible membrane, designed to apply a uniform pressure to the walls of a cavity. The probe consists of a steel tube, 12 millimetres in diameter and 74 mm in length, with a hole in the mid-portion of the main body. There are six main components of the H-Ometer, namely, the main body, head connector, special clip, tail, tubing and membrane. The head connector joins the main body to the tubing, which is attached to a control unit. The special clip consists of a ring that secures the membrane to the main body, which represents a major pa rt of the measuring device and has a hole in its mid-portion. The tail, located at the lower end of the probe, fastens the membrane to the probe. The membrane is made from rubber of high elasticity and is between 0.5 mm to 1.0 mm thick. The illustration at right shows the schematic diagram of the H-Ometer.

Generally, when measurements of tensile strength of rock and hard soil are carried out, there is a need to cut samples to a particular shape using the appropriate equipment. This is sometimes difficult to achieve, especially on weak materials such as weak rock and hard soil. It is also time-consuming and costly. To overcome these problems, it is necessary to have a measuring device that is reliable, simple to use, small, light, portable and inexpensive. The H-Ometer is designed to measure indirectly the tensile strength of weak rock and hard soil, and is reliable, simple to use, portable and can even be used in the laboratory. It is mainly for use in civil engineering works, especially in testing weak materials to gauge their strength. The strength parameters obtained from the H-Ometer tests can then be used in the design of the foundation.

As we know, weak materials and hard soil are difficult to test as they break easily, and they always pose problems to design engineers when their strength parameters are being taken. Weak rocks are often characterized by difficulties in obtaining intact and reliable samples for laboratory testing...