From the new Austrian tunneling method to the geoengineering condition evaluation and dynamic controlling method

The new Austrian tunneling method （NATM） is widely applied in design and construction of underground engineering projects. When the type and distribution of unfavorable geological bodies （UGBs） associated with their influences on geoengineering are complicated or unfortunately are overlooked, we should pay more attentions to internal features of rocks grades IV and V （even in local but mostly controlling zones）. With increasing attentions to the characteristics, mechanism and influences of engineering construction-triggered geohazards, it is crucial to fully understand the disturbance of these geohazards on project construction. A reasonable determination method in construction procedure, i.e. the shape of working face, the type of engineering support and the choice of feasible procedure, should be considered in order to mitigate the construction-triggered geohazards. Due to their high sensitivity to groundwater and in-situ stress, various UGBs exhibit hysteretic nature and failure modes. To give a complete understanding on the internal causes, the emphasis on advanced comprehensive geological forecasting and overall reinforcement treatment is therefore of more practical significance. Compre- hensive evaluation of influential factors, identification of UGB, and measures of discontinuity dynamic controlling comprises the geoengineering condition evaluation and dynamic controlling method. In a case of a cut slope, the variations of UGBs and the impacts of key environmental factors are presented, where more severe construction-triggered geohazards emerged in construction stage than those predicted in design and field investigation stages. As a result, the weight ratios of different influential factors with respect to field investigation, design and construction are obtained.

Research on head way control of a guided transport system based on intersection condition evaluation

ln order to ensure the safety and efficiency of the section tracking operation of a guided transport system,a safety headway control method of section tracking based on intersection conditions is proposed in this paper.Considering the difference of signal phase,the evaluation model of road conditions was established based on a fuzzy comprehensive evaluation method,FAGT.Based on the artificial potential field method,the time-varying hybrid artificial potential field(TH-APF)method was proposed,and the tracking headway control algorithm was designed to realize the dynamic control of the tracking headway of the guide transport vehicle.The simulation results verified the effectiveness and applicability of the evaluation model of intersection road conditions;the tracking headway can be maintained at about 120 s.The tracking headway control algorithm of guided transport vehicles can respond to the road conditions and avoid the local optimum of the artificial potential field method,thus improving the operating efficiency.

Motor oil condition evaluation based on on-board diagnostic system

The condition of the motor oil in civilian cars is difficult to monitor;hence,we propose a method to evaluate the degree of degradation of motor oil using an on‐board diagnostic(OBD)system.Three civilian cars and four motor oils(containing mineral oils and synthetic oils)were subjected to five groups of road tests under urban traffic and high‐way conditions.The operation information,oil service time,mileage,engine operation time,idle time of the engine,and number of start‐ups of the engine were obtained using the proposed OBD system.Physiochemical properties and changes in the components of motor oils during road tests were analyzed in laboratory.The theoretical model of the comprehensive indicators of driving parameters and oil properties were established.The proposed method was successfully applied to different cars,motor oils,and operating conditions in road tests.All the theoretical models had high accuracy and precision.Herein,we provide a method to monitor the oil condition with real‐time driving parameters and provide a reference for end users to change their motor oil reasonably.