Reasonable Smooth Blasting Factor Used in Tunnel

The fact of tunnel smooth blasting is those reduce over break and minimize fracturing of the rock at the boundary of an excavation. The select ruler and assured method of smooth blasting parameter are discussed, and the quality check standard of the smooth blasting, based on the under and over-break (5~15 mm), the circumferential hole mark ratio (>50%) and rock fragment, are found. A good benefit is gotten as these used in one tunnel.     

THEORY AND PRACTICE OF SMOOTH BLASTING

A practical technique of smooth blasting in the formation rocks at qinjina coal mine in this paper is introduced. Based on the principal of smooth blasting, the relation between charge concentration, charge structure, spacing, discoincidence coefficient and coefficient of closely holes is respectively discussed. According to the theory of rock mechanics, the applied condilions is analysed.     

Seismic Effect Analysis of Cutting Blasting Digging in High Way

A seismic effect is main harm in engineering blasting. By analyzing Seismic velocity and frequency of the main control factors of them, according to the data measured on the spot, the relation formula among Seismic velocity and dynamite and the distance between blasting fountain are obtained. Effects on buildings produced by vibration frequency and differences between blasting earthquake and natively seismic are analyzed. The calculation of blasting safety distance and selecting standard of breakage judge are studied and validated. The results of experiment and research indicate that we should attach importance to blasting seismic rules and effects on different buildings in order that basting techniques bring much economy benefits and reduce harm of blasting vibration as possible as much.     

Smooth blasting design and optimization of large spanurban highway tunnels

Vibration resistance can be incorporated into blasting designs to avoid damages caused by the excavation of large span tunnels in busy urban areas, but only by basing excavation design schemes on actual situations. In view of the actual situation in the Jahua tunnel in Chongqing, P. R. China, research was conducted to identify a relevant explosion scheme. The research was based on theoretical analysis and in situ testing. Face step excavation was considered in the broadening band A, and upper drift excavation was adopted in broadening bands B, C, D and E. We simultaneously proposed selection criteria for smooth blasting parameters and the construction layout of broadening band B. Based on a regression analysis of the blasting vibration monitoring results, a spread orderliness of blasting vibration was drawn. Explosion parameters optimization measures were put forward, selected from the maximum charge quantity, millisecond blasting, reasonable blasting time difference, and the excavation plan. Field testing achieved satisfactory results. These findings will play an important role in guiding excavation blasting construction of tunnel projects and assuring the safety of ground buildings.     

Research on Control and Safety Analysis in Demolition Blasting of Tower Buildings

In this paper,integrating the principium of demolition blasting of buildings and the practice,the general mechanism and affection factors of blasting harms such as blasting shock,collapsing shock,blasting rock,blasting shock wave and blasting noises produced in demolition blasting of buildings are analyzed.The safety problems existed in demolition blasting of buildings are discussed from three aspects such as the unsafe behavior of "person",the unsafe state of "substance"and the unsafe condition of "environment".Based on an engineering example,the difficulty of safety blasting of engineering example was analyzed,on this basis,corresponding effective safety defending measures and the method of safety control are brought forward.This study is significant to the construction safety and control of demolition blasting of similarity tower building in practice.     

THE DIRECTING MECHANISM OF V-NOTCHF WITHJN V-NOTCHJNG BLASTING

Based on the blasting theory and "Fracture Mechanics " , the directing effect mechanism of V-netch in V-rotching blasting is studied and the positive splitting and directional explanding of crack within V-notching blasting and the priority of crack's expanding in the V-notch axle-plane etc are expounded. It's just these fracture characteristics mentioned above that ensure the fine control of the cracking plane.     

A FRACTURE MECHANICS ANALYSIS OF FRACTURE PLANE CONTROL IN FRACTURE CONTROL BLASTING

A procedure of fracture control blasting for achieving directional breaking of rocks by blasting is presented. The criterion for initiating of radial cracks in borehole wall under dynamic load and the method for determining the permissible rang of initial gas pressure (p0) in the charge cavity are developed .and the branching of radial cracks and the effeets of the pressure (p0) and blasthole geometry (R0.a.L3) on final dimensions of directed cracks are studied .with Fracture Mechanics analysis in all three aspects of fracture process including crack initiation .crack propagation and crack arrest.     

The Application of Pre-splitting Blasting to Excavation on High Slope in Soft Rock Section

Based on analyzing about blasting mode of slope in the construction of road, the paper shows that pre splitting blasting is mostly suitable in the section of severely weathering soft rock with developed joints and fractures, introduced the laying out about the hole of pre splitting blasting that can apply in the high slope of the expressway in the section, and designed the parameter. The practice shows that it gained favourable effect by this method.     

A Synthetic Optimum Seeking Method for Blasting Plans in City Environment

The conditions of city environment to restrict blasting engineering are introduced into the standard of evaluating the blasting plan.Using fuzzy mathematics, a synthetic optimum seeking method is established for the blasting plans of loosening rockmass in this paper, The method was applied to a rockmass-blasting project, and the results demonstrated that the method is quite effective.     

Influence of blasting vibration on adjacent buildings of station tunnel

The influence of blasting vibration on the adjacent buildings is inevitable if blasting is employed for excavation. Daping station tunnel of Chongqing light railway project, on which there is dense with population and buildings, has a minimum buried depth of only four meters and maximum span length of 26.3 meters. The stepped excavation mode with short hole, multi round and V shaped cut are adopted. The maximum charge weight of one delayed interval is determined by the permitted vibration velocity. The smooth blasting technology with adding vibration reduction holes is used. Meanwhile, the charge weight per hole is strictly controlled. With the simulation and on site test, it is found that the proposed technology for tunnel construction is feasible.     

Parameters of Spiral V-notch Loosen Blasting

Based on the mechanism of spiral V notch loosen blasting,uncoupled explosive loading is adopted to prevent the explosion waves from breaking the wall of the blasting hole. Relative parameters of spiral V notch are analyzed and their calculating formulae are achieved. The expressions of the width of the blasted crack,the length of the developed crack and of the sizes of the blasted lumps are obtained. The relationship between the blastyed effect, the spiral angle, and the notching angle is studied, which provides a theoretical base for developing a blasting strategy with desirable lump sizes.     

Design of Reef- blasting Project and Analysis of Regulation Effect for Fuling to Tongluo Canyon Reach in Three Gorges Reservoir Region

After the completion of the Three Gorges project,the navigation conditions of the reservoir region will be improved evidently,which has laid the foundation for straight run of the 10,000-ton-class fleet to Chongqing Port,and is the promotion of the development of shipping in Yangtze River.But according to the standard of the 10,000-ton-class fleet,there are still some reaches of the reservoir region can not meet the requirements of the waterway on smooth and safe navigation.Therefore,some regulation measures should be adopted to eliminate these obstructions.It is one of the important parts in the reservoir region waterway regulation work for the Fuling to Tongluo canyon reach blasting project.30 reef obstacle blocks of 14 reaches in this project were removed by blasting.Based on the analysis of obstruct features of various rocks,according to the standard of the 10,000-ton-class fleet,the design parameters and blasting regulation program were put forward,and the regulation effect is analyzed and forecasted.     

A STATIC STRESS ANALYSIS OF THE EFFECT OF STRATIFICATION PLANE OF ROCK MASSES ON SMOOTH BLASTING

The influenfial factors of stratification plane to smooth blasting are studied according to the ti eory of smooth blasting and the anslysis of static stress. The results show that the angle p between the maximum principal plane and the rertical line of stratification plane has some influence on the fracture of rock masses.     

Experiment Research of Pre-splitting in Bedded Composite Cutting Blasting Digging

The rock property difference of bedded composite rock often does not lead to ideal Pre-splitting blasting effect. The influence factor of Pre-splitting such as the dynamite quantity and explosive structure was studied by experiment with transient dynamic strain gauge testing system. At the same time, the damaged rock reduced by blasting was examined with RS-STOIC ultrasonic gauge. The results indicate that different dynamite densities are taken for considering especially property of bedded composite rock. The conclusion for cite.     

The Mechanism of Smooth and Pre-Cracking Blasting

The paper discusses some main factors of the mecha nism of smooth and pre-cracking blasting.The results of theoretical analyses show that the formation of directional cracks isrelated to the distan ce of holes.the quasi-static pressure and the strueture of rock mass. This paperalso studies the relation of len gth of crack and distance of holes.The initial cracks occur on the wallof holes instead of in the middle of two holes.     

The Indoor Experiment Study on Pore Water Pressure Increment and Dissipation of Saturated Sand Caused by Blasting

An indoor experiment on explosive compaction of saturated sand has been done.The changes of pore water pressure during blasting are measured and the laws of pore water pressure increment and dissipation are analyzed.It indicates that the processes of increment and dissipation of pore water pressure have particularity along the depth and radial.At the same time,the development rule of liquefaction under explosive loading is also analyzed;these conclusions obtained in the experiment,may provide some useful references for the engineering design and the theoretic study of explosive compaction for water-saturated granular foundation.     

Study and Implementation of Digital Flame Image Inspect System for Power Plant Boiler

Aiming at the shortcoming of modern power plant flame image inspect system that is based on on_off logicals,the article design a new power plant flame image inspect system based on general video capture hardware. A best optimize image segmentation arithmetic is given for image pretreatment. Based on human cognize character, the paper puts forword a Weightiness Amend Coefficient(WAC). for the purpose of enhancing the intelligent and auto_adoptions to complex combustion condition, a new Cluster Center Initiative Optimize and Auto_adoptions Rework arithmetic is put forword. At last, the experimentation result is given.     

Method for Calculating Steady Vibration Response of Shafting with Local Nonlinearity

A method which is used for calculating steady vibration response of shipping propulsion shafting connecting with a coupling with nonlinear hysteresis characteristics are studied. On condition that the nonlinear dynamic stiffness and hysteresis damping of the coupling be considered, on the basis of GLM(Galerki Levenberg Marquard) method, a method called SSGILM(Separate System Galerkin and Improved Levenberg-Marquardt)to be used for calculating steady vibration response of propulsion shafting with local nonlinear dynamic stiffness and hysteresis damping, is proposed. A simple example is given out and the analyses show that it is effective to calculate steady vibration response of the shafting with local nonlinear dynamic stiffness and hysteresis damping by SSGILM method. From initial response values given arbitrarily, the automatic search algorithm in SSGILM method can converge the given initial response values to the response values accorded with required accuracy quickly; nonlinear dynamic stiffness and hysteresis damping of the coupling have different effect on vibration response of the shafting at different range of frequency. At the area of close nature frequency of the shafting ,displacement amplitude of the shafting is bigger. Beyond the range, the characteristics of the coupling have restraint effect on vibration of the shafting.     

Analysis on the influence from rectangle cavity behind the lining to the primary support of tunnel

In process of the tunnel construction throw New Austrian Tunnelling Method, the result of smoothwall blasting to rock tunnel is not good, there are more and more cavities produced behind the lining. On the basis of engineering project, this paper makes the three-dimensional elastic-plastic analysis throw numerical simulation, discusses the stress-strain behavior of primary support when there is a different size of rectangle cavity behind the lining. In addition the safety factor of tunnel is calculated with cavity based on the strength reduction finit element method. This factor is compared with the factor of health tunnel. The stability of tunnel structure system is estimated through the linear regression analysis between stress of lining and safety factor.     

AtTPS03基因RNA干扰载体的构建及拟南芥转化

本研究以拟南芥DNA为模板,将罗勒烯合成酶AtTPS03基因的一个目的片段克隆到T-载体上.对克隆片段测序后,进行Blast比对,结果目的片段的序列与GenBank上报道的序列同源性达到100%.根据RNA干扰的基本原理,将目的片段正反向连到干扰载体pFGC5941查尔酮内含子的两侧,经限制性酶切和PCR扩增检测,证明已成功构建了干扰载体P-2AT03.利用农杆菌介导的浸花法转化拟南芥.收获的种子在含草丁膦的培养基上筛选抗性苗,通过对抗性苗的PCR检测,已成功获得了12株转基因苗.这些转基因苗为进一步研究罗勒烯和罗勒烯合成酶的功能奠定了良好基础.