| The initial stress conditions for soil elements beneath the foundation under the building are usually rather complex. Before subjected to complicated cyclic loading induced by ocean wave and earthquake shaking, the initial principal stress of soil elements and the initial direction angle of maximum principal stress are usually changes. Under this condition, the dynamic behavior of soils and the constitutive relation are very complicated. So it is very necessary to develop the experimental apparatus that can simulate complex condition of initial consolidation and cyclic shear.The author introduced how to design and implement the computer control and data Sampling and Processing System of Soil Static and Dynamic Universal Triaxil and Torsional Shear Apparatus and performance of the system in this paper. With modern computer technology, the author made the data Sampling and Processing part of system can inspect the data of test on time, sampling dynamic stress, dynamic strain and dynamic pore pressure on time during the whole process of test, display and save data files on line, processing the data files after the test. The system not only makes data processing and data sampling entirely automatic but also succeeds in a series of difficult problems, such as calculation of the area of hysteresis loop and other irregular cure, and common tangent of Mohrs circle. In the controlling part of system, considering some possible variations of the frequency of the input signal, the author used the single neuron adaptive PID controller to reconstruct the control system to achieve the adaptive control of triaxial and torsional test. The single neuron adaptive PID controller will make rapid improvement of the control precision and robustness of control system.Now the system has been used in the experiment of soil stress. It helped the people to get many useful data. It proved the performance of the system are advanced.
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