To study the relationship between grouting effect and grouting factors, three factors (seven parameters) directionless pressure and small cycle grouting model experiment on sandy gravel was done, which was designed according to uniform design method. And regressing was applied to analysis of the test data. The two models test results indicate that when the diffusing radius of grout changes from 26 to 51 cm, the grouted sandy gravel compressing strength changes from 2.13 to 12.30 MPa; the relationship between diffusing radius(R) and water cement ratio(m), permeability coefficient(k), grouting pressure(p), grouting time(t) is R=19.953m 0.121 k 0.429 p 0.412 t 0.437 ; the relationship between compressing strength(P) and porosity(n), water cement ratio, grouting pressure, grouting time is P 0.984n 0.517 m 1.488 p 0.118 t 0.031 . So the porosity of sandy gravel, the permeability coefficient of sandy gravel, grouting pressure, grouting time, water cement ratio are main factors to influence the grouting effect. The grouting pressure is the main factor to influence grouting diffusing radius, and the water cement ratio is the main factor to influence grouted sandy gravel compressing strength.
Faced with the problem of time-delay in the structural active control, the active control based on the output vector prediction in the structural vibration is proposed. Also, the thesis devises a plan of forecast active control, where the gray model GM(1,1) is used as the prediction model and the Matlab program is applied to the Computer Simulation Analysis. Adopting the plan in the aseismatic control of a 5-floor building and comparing the computation results with the control effect acquired from the references , numerical simulation results show that the gray forecast active control can lessen the time-delay effects on the structural vibration control which is superior to that in the references .
Application of ultrasonic in strength measurement of similar materials of limestone ® LIU Tie-xiong(30|t~Pt~) t,2, PENG Zhen-bin(~[~-~) ~ , HAN Jin-tian(~il~ []) 2 (1. Abstract: Similar materials such as cement, gypsum and sand are options for simulating limestone characteristic. A series of reasonable proportions are chosen to do similar experiments of Karst roof based on the proportions testing of small samples indoors. Applying on ultrasonic, the velocities of transverse wave and vertical wave of similar samples have been inspected with the sound wave instrument. Dynamic modulus of elasticity and Poisson's ratio of the samples have been educed. According to the testing data, the relationship between the transverse wave and vertical wave velocity, compressive strength and anti-bend strength are analyzed. It has been proved that the vertical wave velocity is better for reflecting compressive strength and anti-bend strength of similar materials than the transverse wave velocity. The vertical wave velocity increases with the strength and dynamic modulus of elasticity.
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