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Carriage positioning is the prerequisite process for the automatic control of the drilling of the drill rig. The original method is only feasible in the ideal working face has no stone stacked. The carriage of drill rig is tilted laterally when there are stones stacked. The push beam can be rotated laterally around the laser beam. The angular variable cannot be locked, and there is an infinite solution to the pose of the carriage, resulting in a large positioning error or even unusable. In order to solve this problem, a new method of using the booms in dual sides to participate in positioning is proposed. It is theoretically proved the feasibility, and the problem of finding the unique solution of the carriage pose is solved to solve the vertex position of the triangle when the length are fixed; the transformation relationship of the carriage-laser coordinate system is determined based on the D-H method and the coordinate system translation; the set condition is introduced to find the actual origin position of the carriage coordinate system, and the angular values of the dual sides of the drill rig are calculated by MATLAB programming. Solve the pose matrix of the carriage coordinate system in the working face coordinate system to realize the carriage positioning. The field test results show that the new method fully adapts to the height change of the stone condition, and can quickly determine the actual position and pose of the carriage; the vertical positioning error of the carriage is within 5%. Drilling positioning accuracy is within 12 cm when the error compensation method is not used. By comparing the influence of two methods on the drilling positioning effect, it is found that the original method has the phenomenon that the positioning error is transmitted to the non-positioning side boom. When measured data of total station are accurate, the average positioning error of blast-holes in the non-positioning side is 94% higher than that in the positioning side. There is no such problem with the positioning of the new method. The positioning accuracy of the blast-holes in dual sides is consistent with that in the positioning side of the original method, which is advantageous for error compensation. The new method has been successfully verified in the roadway and is universal. It can be utilized to the positioning of the same type of drill rig. [ABSTRACT FROM AUTHOR]

Vibration velocities allowed for different buildings and structures around tunnel which is excavated by blasting are different in urban area. The computation of blasting charge which could control different vibration velocities within the value allowed for all nearby buildings was very difficult for blasting design in the past. With a case study of the tunnel blasting engineering in Chongqing city，the space loci equations of tunnel and the building protected outline are established.The functional relationship of the blast charge and tunnel site are respectively studied under three safe vibration velocities corresponding to the subway，the historic building and other buildings. The tunnel curve is divided into several sections by lengthening the building outline，the function about blasting charge and tunnel location is deduced for the historic building outside the tunnel. The blasting charge which vibration is controlled within safety standard is obtained by formula on the basis of space distance from detonating site to the line of subway. The blasting charge for other buildings is calculated based on that the ground above tunnel is distant from blasting point on the condition of vibration speed allowed. These three charge values at every position of the tunnel are calculated by Matlab program，and the minimum of three values is selected as the design blasting charge. [ABSTRACT FROM AUTHOR]

Different blasting parameters may have different effects on driving speed in hard rock roadway development. The method of numerical simulation and field test from the coal mine of Guangneng Company was used to study the effects of different blasting parameters in this paper. The length and angle range of borehole were designed on the basis of drilling speed and boom' length for drilling jumbo. According to the data of the experiment mine, five blasting models were constructed by means of 3D numerical simulation. The transient stress, destructive range and advance per attack of cutting area were quantitatively analyzed and compared when blasting parameters (cutting angle, blasting charge, cut centre is or isn't blasted) were changed. The results show that the cut angle changes within a narrow range under the conditions that hydraulic rock-drilling jumbo was used, so the advance per attack was rarely influenced by cutting angle’s variation. The average value of effective stress in the key cutting area increased by 46.4%-76.7% when center holes were blasted than when weren't with 1.2 kg blasting charge, the destructive areas of chief sections improved by 24.7%-51.8%. The increase of excavation speed wasn't obvious when blasting charges were only added under the condition that the center hole of cutting area was simultaneously blasted. The blasting charge increased up to 50%, the destructive areas of chief sections improved by 8.5%-13% accordingly, and the blasting footage enhanced by 2%-10% only. The study indicates that it has a key influence on blasting footage that the center hole of cutting area is blasted in hard rock excavation. [ABSTRACT FROM AUTHOR]