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Ultimate pullout resistance of single vertical anchors
REINFORCEMENT:BOLTS & ANCHORS 956217 Prediction of drill-bit performance using multi-variable linear regression analysis A. Ersoy & M. D. Waller, Transactions - Institution of Mining & Metallurgy, Section A, 104(May-Aug), 1995, pp AlOl-A114. Drill-bit performance is affected by a range of factors. However, the principal factors that require consideration in predicting drilling rates are the type of bit, the bit operating parameters and the charactersitics of the penetrated rock. A single index is not a sufficient basis for predicting performance. A variety of rock types were drilled in the laboratory with polycrystalline diamond compact (PDC) and impregnated diamond core bits using a full instrumented drilling rig at different rotational speeds and with a range of weights on the bit. Quantitative determinations of a wide range of textural, mechanical and intact rock properties were also made. Multi-variable linear regression analysis was then used to develop predictive models of rates of penetration from the operating and rock property data. The models have been verified by statistical tests. The analysis indicated that the models for the pin and hybrid PDC bits have potential for practical application. (Authors) 956218 Maiateaaace ia the miaiag aad metalkwgical industries. Proceedbgs of a conference and workskop, Woihgoag, October 1994 ed A. Hargraves & J. Montagner, (Australasian Institute of Mining 8s Metallurgy/University of Wollongong), ISBN (paperback) 0 949106 984, 1994, pp 344. These proceedings cover the many aspects of machine maintenance discumed at the conference. The opening papers emphasise maintenance as a pivotal function, worthy of management attention, that can be used as a source of competitive advantage. Case histories provide specific examples of maintenance in environments as diverse as coal mines and high-speed train systems. Strategies, technologies, techniques and disposal of waste from such programs are presented in detail. (S.E.Long) 956219 Study of contaminant wear engineering theory and its appliatioa (in Chinese) Jia Ruiqing, Xia Zhixin & Shao Hesheng, Journal - China Coal Society, 20(l), 1995, pp 63-66. Based on analysis of contaminant wear of hydraulic components, a series of technical parameters are proposed, i.e., the contaminant wear strength, ok, the contaminant wear factor, fm, lubricity coetlicient, b, flexibility factor, I,, material coetB&nt, b. These parameters were tested by MMU-5 test rig for fluid contaminant friction wear. Finally, application of the engineering theory is discussed. (English summary)
ROCK AND SOIL REINFORCEMENT AND SUPPORT General 956220 Selection of support systems for underground openings in coal mines based on neural network (in Ckinese) Feng Xiating & Lin Yunmei, Journal - China Coal Society, 20(l), 1995, pp 34-38. A novel approaach to selecting support systems for underground openings is described. It is based on self-learning and adaptive recognition of neural network. Data is first obtained from a case study to establish support systems for roadways.
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An intelligent reasoning network is established between geological conditions of rockmass and support systems. Then it is popularized. The results show that the neural network can establish a good reference relation between the geological characteristics of projects and support systems. (from English summary) 956221 Prediction of intervals of main roof weigbtlng by an artificial neural network (in Clhese) Zhang Qing, Nie Xiaoyan, Wei Liping & Liu Ming, Journal China Coal Society, 20(l), 1995, pp 25-28. The intervals of main roof weighting at work faces were predicted by using artificial neural network. Twenty eight factors influencing the weighting intervals were determiued, including geological and mining conditions and the effects of mining. The data obtained from in-situ measurem em were collected and regarded as learning samples. BP algorithm was used for learning and for prediction. The neural network is similar to regression analysis. However as compared with general multi-variant non-linear regression, it has the following merits: no limitation to the number of inputs qualitative parameters can be input and high accuracy in prediction. (English summary)
Bolts and anchors 956222 Ultimate pullout resistance of siugle vertical anchors A. Ghaly 8s A. Hanna, Ca~~aaXanGeotechnical Journal, 31(5), 1994, pp 661-672. An investigation into the performance of single vertical screw anchors installed in sands is presented. Models were developed employing the limit equilibrium method of analysis to predict the uplift capacity of anchors installed into shallow, transition, and deep depths. Weight and shear factors for shallow and deep anchors are established to simplify the calculation of the uplift capacity from the theories developed. The effect of sand overconsolidation resulting from the application of mechanical compaction was introduced by incorporating the overconsolidation ratio in the uplift capacity calculations. (from Authors) 956223 Ultimate pullout resistance of groups of vertical anchors A. Hanna & A. Ghaly, Canadian Geotechnical Journal, 310, 1994, pp 673-682. A theoretical investigation on the group action of vertical scmw anchors installed in sands is presented. An experimentally observed rupture surface for single anchors was employed to establish the shape of the rupture surface for groups of anchors. A theory was developed to predict the uplift capacity of groups of anchors with d&rent configurations utilizing the theoretical model described in a companion paper. The effect of overconsolidation due to the compaction technique used in placing the sand was incorporated in the theoretical calculations of uplift capacity. An empirical equation, based on theory and experimental data, is proposed to mathematically quantify the effect of densification on the angle of shearing resistance of the sand. (from Authors) 956224 Effeetive fastening of the bottom of the stilhg basin of a bigb-bead dam by prestressed asckts V. N. Zhivoderov & N. I. Tupikov, Hydrotechnical Construction, 28(4), 1994, pp 243-252; translated from: Gidrotekhnicheskoe Stroitel’stvo, 4, 1994, pp 40-46. Passing of flood water over a prolonged period of time resulted in damage to the stilling basin platform at the
ROCK AND SOIL REINFORCEMENT AND SUPPORT General 956220 Selection of support systems for underground openings in coal mines based on neural network (in Ckinese) Feng Xiating & Lin Yunmei, Journal - China Coal Society, 20(l), 1995, pp 34-38. A novel approaach to selecting support systems for underground openings is described. It is based on self-learning and adaptive recognition of neural network. Data is first obtained from a case study to establish support systems for roadways.
219A
An intelligent reasoning network is established between geological conditions of rockmass and support systems. Then it is popularized. The results show that the neural network can establish a good reference relation between the geological characteristics of projects and support systems. (from English summary) 956221 Prediction of intervals of main roof weigbtlng by an artificial neural network (in Clhese) Zhang Qing, Nie Xiaoyan, Wei Liping & Liu Ming, Journal China Coal Society, 20(l), 1995, pp 25-28. The intervals of main roof weighting at work faces were predicted by using artificial neural network. Twenty eight factors influencing the weighting intervals were determiued, including geological and mining conditions and the effects of mining. The data obtained from in-situ measurem em were collected and regarded as learning samples. BP algorithm was used for learning and for prediction. The neural network is similar to regression analysis. However as compared with general multi-variant non-linear regression, it has the following merits: no limitation to the number of inputs qualitative parameters can be input and high accuracy in prediction. (English summary)
Bolts and anchors 956222 Ultimate pullout resistance of siugle vertical anchors A. Ghaly 8s A. Hanna, Ca~~aaXanGeotechnical Journal, 31(5), 1994, pp 661-672. An investigation into the performance of single vertical screw anchors installed in sands is presented. Models were developed employing the limit equilibrium method of analysis to predict the uplift capacity of anchors installed into shallow, transition, and deep depths. Weight and shear factors for shallow and deep anchors are established to simplify the calculation of the uplift capacity from the theories developed. The effect of sand overconsolidation resulting from the application of mechanical compaction was introduced by incorporating the overconsolidation ratio in the uplift capacity calculations. (from Authors) 956223 Ultimate pullout resistance of groups of vertical anchors A. Hanna & A. Ghaly, Canadian Geotechnical Journal, 310, 1994, pp 673-682. A theoretical investigation on the group action of vertical scmw anchors installed in sands is presented. An experimentally observed rupture surface for single anchors was employed to establish the shape of the rupture surface for groups of anchors. A theory was developed to predict the uplift capacity of groups of anchors with d&rent configurations utilizing the theoretical model described in a companion paper. The effect of overconsolidation due to the compaction technique used in placing the sand was incorporated in the theoretical calculations of uplift capacity. An empirical equation, based on theory and experimental data, is proposed to mathematically quantify the effect of densification on the angle of shearing resistance of the sand. (from Authors) 956224 Effeetive fastening of the bottom of the stilhg basin of a bigb-bead dam by prestressed asckts V. N. Zhivoderov & N. I. Tupikov, Hydrotechnical Construction, 28(4), 1994, pp 243-252; translated from: Gidrotekhnicheskoe Stroitel’stvo, 4, 1994, pp 40-46. Passing of flood water over a prolonged period of time resulted in damage to the stilling basin platform at the