Dear all, Why we place two strain transducers and two piezoelectric accelerometers at diametrically opposite locations in the dynamic pile load test? It seems to me that 4 strain transducers and 4 piezoelectric accelerometers at 90 degrees OR 2 strain transducers and 2 piezoelectric accelerometers at perpendicular positions would cancel the bending and the temperature effects. I appreciate your answers. Thanks.
You are right. For redundancy, you should install two "sets" of transducers diametrically opposed, i.e. four locations. If one transducer fails, then you can rely on the other "set". Your second option of installing transducers at 90 degrees will not acheive a redundant system for you!