發(fā)布時(shí)間：2018-08-01 14:09

【摘要】：城市地鐵鉆爆法修建過程中,由于巖體開挖的位置距地面較近,對(duì)爆破振動(dòng)控制嚴(yán)格。電子雷管的使用使精確微差延期成為現(xiàn)實(shí)。越來越多的地鐵爆破施工采用電子雷管起爆技術(shù),電子雷管爆破在改善巖石破碎效果、減小爆破振動(dòng)強(qiáng)度方面有著無可比擬的優(yōu)勢。目前爆破工程界還未建立微差延期間隔與巖石破碎和振動(dòng)控制效果間的理論關(guān)系,現(xiàn)場施工更多依靠經(jīng)驗(yàn)和多次試驗(yàn)確定電子雷管延期時(shí)間,對(duì)地鐵隧道精確延時(shí)的爆破振動(dòng)控制進(jìn)行深入研究已迫在眉睫。本文依托國家自然科學(xué)基金“圍壓環(huán)境爆破荷載作用下地下結(jié)構(gòu)累積損傷動(dòng)力響應(yīng)特性研究(51374212)”,以北京地鐵、深圳地鐵等地鐵隧道鉆爆法施工為工程背景,對(duì)地鐵隧道精確延時(shí)爆破振動(dòng)控制進(jìn)行了深入研究分析。采用理論計(jì)算、現(xiàn)場試驗(yàn)和數(shù)值計(jì)算等方法,從改善巖石破碎效果、減小爆破振動(dòng)強(qiáng)度兩方面探討了精確延時(shí)的合理孔間延期和段間延期時(shí)間,分析了地鐵隧道爆破對(duì)鄰近隧道結(jié)構(gòu)和地面建筑的影響,研究內(nèi)容主要有以下幾個(gè)方面:(1)基于已有的HHT方法在爆破信號(hào)分析方面的不足,提出了相應(yīng)的改進(jìn)措施。通過計(jì)算分解時(shí)間、不同迭代次數(shù)的過度極值和對(duì)不同分解次數(shù)得到的各IMF分量與原始分量的相關(guān)系數(shù)的計(jì)算結(jié)果,得到了CEEMD的合理的集總平均次數(shù)為200—300次。提出了數(shù)據(jù)內(nèi)部端點(diǎn)極值點(diǎn)的確定、數(shù)據(jù)外部非平穩(wěn)信號(hào)向平穩(wěn)信號(hào)過渡階段的數(shù)據(jù)擴(kuò)展和過渡段向平穩(wěn)信號(hào)延拓的數(shù)據(jù)延拓“過渡段—平穩(wěn)段”的信號(hào)端點(diǎn)處理方法。將提出的端點(diǎn)處理方法嵌入CEEMD中,對(duì)仿真信號(hào)和實(shí)際信號(hào)的分解結(jié)果表明,該方法保留了原始信號(hào)在端點(diǎn)處的延伸趨勢,減小了迭代次數(shù)和由高頻間歇噪聲等造成的信號(hào)突變形成的包絡(luò)線“欠沖”和“過沖”,剔除延拓的數(shù)據(jù)能保證原始數(shù)據(jù)不受到端點(diǎn)波動(dòng)的影響。(2)將解相關(guān)算法嵌入CEEMD分解中,采用本文提出的端點(diǎn)處理方法、解相關(guān)算法和CEEMD方法的信號(hào)聯(lián)合處理方式,能有效的抑制信號(hào)模態(tài)混疊現(xiàn)象,避免虛假分量帶來的能量損失。仿真信號(hào)的計(jì)算結(jié)果表明,該方法分解精度比EMD和CEEMD高,處理信號(hào)內(nèi)模態(tài)混疊和虛假分量的效果較好,通過多次迭代計(jì)算可以得到較好的分解效果;同時(shí)基本保證了實(shí)際信號(hào)中每個(gè)IMF內(nèi)非主頻率信號(hào)的能量比例較低。(3)現(xiàn)場試驗(yàn)結(jié)果表明:隧道埋深較大時(shí),由于高頻波被大量吸收,信號(hào)主頻較低,主頻隨距離的變化改變量較小,很難通過設(shè)置電子雷管的微差間隔提高爆破主頻。此時(shí)需通過降低單孔及最大單段藥量來控制爆破振動(dòng)強(qiáng)度。采用三排掏槽孔進(jìn)行爆破施工,從減振效果和提高掘進(jìn)速率兩方面均較雙排掏槽有著明顯的提升�？组g微差的設(shè)置要綜合考慮降低爆破振動(dòng)和提高爆破效果兩方面因素。選擇掏槽孔延期間隔為2ms,其它類型炮孔微差間隔為4ms,在保證爆破振速不超標(biāo)的前提下,加強(qiáng)了圍巖的破碎效果,減少了機(jī)械二次破碎巖石幾率。鄰近隧道迎爆側(cè)振動(dòng)強(qiáng)度遠(yuǎn)大于背爆側(cè),由于上臺(tái)階開挖出的臨空面效應(yīng),使下臺(tái)階整體上爆破振動(dòng)速度小于上臺(tái)階爆破。隧道迎爆側(cè)在掌子面前后1d范圍內(nèi)振動(dòng)強(qiáng)度較大,隧道內(nèi)爆破主頻分布在30—90hz之間,不會(huì)引起鄰近隧道結(jié)構(gòu)的共振,結(jié)構(gòu)的損傷主要受振動(dòng)速度的影響。提出了“速度—頻率—能量”的安全判定標(biāo)準(zhǔn),將信號(hào)中小于20hz的能量比例加入原有安全允許標(biāo)準(zhǔn)中,新提出的標(biāo)準(zhǔn)較以往的安全標(biāo)準(zhǔn)更全面。(4)從爆破振動(dòng)三要素和能量的角度分析了電子雷管和非電子雷管在爆破振動(dòng)控制和改善爆破效果的差異,在隧道截面面積、炮孔布置形式和炮孔數(shù)量整體上基本相同的情況下,電子雷管可以實(shí)現(xiàn)逐孔起爆,爆破振動(dòng)強(qiáng)度較普通毫秒延期雷管有大幅度的下降,并能增加單次爆破進(jìn)尺。采用線性疊加法構(gòu)造不同延期時(shí)間下的爆破疊加應(yīng)力波形,當(dāng)延期時(shí)間在波形主振半周期范圍內(nèi),疊加峰值振速明顯減小,振動(dòng)主頻有不同程度的提升,0—20hz內(nèi)的能量比例同時(shí)會(huì)有較大程度的降低。半周期疊加振速可能并非合成波的最小振速峰值,當(dāng)t/2tt時(shí),疊加振速出現(xiàn)增大的情況;微差爆破的總能量基本小于炮孔同時(shí)起爆時(shí)的總能量,波形半周期及較近時(shí)間范圍內(nèi)總能量有最小值,并出現(xiàn)疊加能量大于單孔能量的情況,證明了實(shí)際應(yīng)用中采用半周期起爆進(jìn)行爆破振動(dòng)控制較難。(5)提出了改善巖石破碎效果的合理孔間和段間爆破延期計(jì)算公式。計(jì)算方法綜合考慮了單孔裝藥量、炮孔與掌子面夾角、裝藥長度、不耦合系數(shù)、巖體性質(zhì)、拋擲巖體的質(zhì)量和體積、炸藥屬性、進(jìn)尺深度等諸多因素。使用電子雷管進(jìn)行精確延期爆破控制確定的延期時(shí)間必須不小于形成新的自由面需要的時(shí)間。根據(jù)計(jì)算結(jié)果,最終確定掏槽孔的孔間延期設(shè)置為3—4ms;內(nèi)圈孔、二圈孔等輔助孔延期設(shè)置為3—5ms。進(jìn)尺為1.0m時(shí),設(shè)置各段別延期間隔為30ms;進(jìn)尺1.5m時(shí),掏槽段采用45ms延期,非掏槽段采用40ms延期間隔;進(jìn)尺在2m時(shí),掏槽段采用50ms大延期間隔,非掏槽段采用45ms延期間隔。(6)鄰近隧道爆破數(shù)值模擬結(jié)果表明:爆破參數(shù)相同時(shí),圓形隧道的結(jié)構(gòu)形式受爆破振動(dòng)時(shí)的響應(yīng)較小,馬蹄形隧道的抗振性相對(duì)較差。上臺(tái)階爆破時(shí)圓形隧道和馬蹄形隧道在迎爆側(cè)拱肩至幫部范圍受到的振動(dòng)強(qiáng)度最大。隨著隧道間距的增大,迎爆側(cè)質(zhì)點(diǎn)振速出現(xiàn)“斷層”式衰減。間距為2.0d時(shí),迎爆側(cè)各部位受到的爆破振動(dòng)強(qiáng)度趨于一致。段藥量相同時(shí),掏槽孔為6炮孔起爆有效的分散爆破能量,并減小了爆破進(jìn)尺,引起的爆破振動(dòng)強(qiáng)度小于4炮孔爆破。隧道間距小于1.0d時(shí),單孔藥量為1.8kg和2.6kg的爆破施工對(duì)結(jié)構(gòu)影響較大,容易造成隧道破壞。三個(gè)方向的最大振動(dòng)速度并非嚴(yán)格出現(xiàn)在與掌子面平行的垂直平面上,振動(dòng)速度在隧道縱向前后5m范圍內(nèi)呈振蕩變化。(7)提出了考慮相鄰炮孔間距的隧道迎爆側(cè)孔間延期的計(jì)算公式。合理的延期時(shí)間主要與相鄰炮孔到監(jiān)測點(diǎn)的距離差、單孔藥量、爆心距和巖體性質(zhì)有關(guān)。在一定距離內(nèi),相鄰炮孔到監(jiān)測點(diǎn)的距離差對(duì)延期時(shí)間的影響最大、爆心距次之、單孔藥量對(duì)延期時(shí)間的影響最小。迎爆側(cè)不同位置,得到的孔間最佳延期時(shí)間存在差異。計(jì)算結(jié)果同時(shí)要符合形成新的自由面的最短延期時(shí)間的要求,即不小于3ms。選取圓形隧道相同爆破參數(shù)在不同延期時(shí)間下的振動(dòng)波形分析。結(jié)果表明合理的延期時(shí)間下,信號(hào)相鄰應(yīng)力波的波峰和波谷相遇的比例較大,減小了峰值振速,并能提高振動(dòng)主頻。隨著延期時(shí)間的增加,爆炸應(yīng)力波施加于同一位置的荷載逐漸分散,減少了相鄰波形峰峰疊加概率,峰值能量得到有效控制。數(shù)值模擬的結(jié)果和理論計(jì)算結(jié)果基本一致,提出的計(jì)算公式切實(shí)可行。隧道不同的部位,應(yīng)力波的減振效果不同。迎爆側(cè)拱肩和幫部在微差爆破時(shí)的振動(dòng)速度遠(yuǎn)小于炮孔同時(shí)起爆的振速。延期時(shí)間較小時(shí),迎爆側(cè)甚至出現(xiàn)小延期爆破振動(dòng)強(qiáng)度大于炮孔同時(shí)起爆的情形。綜合考慮炮孔間距的差異對(duì)疊加振速的影響,形成新的自由面的最小延期時(shí)間和實(shí)際監(jiān)測到的不同延期下隧道迎爆側(cè)最大振速的變化情況,在相鄰隧道不同間距下,給出不同隧道間距下掏槽孔為4炮孔,單孔藥量2.6kg時(shí)孔間延期為5—6ms;單孔藥量1.2kg時(shí),孔間延期為3—5ms;掏槽孔為6炮孔,單孔藥量1.8kg時(shí),孔間延期為4—6ms。(8)對(duì)不同延期時(shí)間下的掏槽孔爆破實(shí)測波形的反應(yīng)譜和CEEMD分析可知,輸入信號(hào)的振動(dòng)強(qiáng)度是影響反應(yīng)譜面積最主要因素,歸一化反應(yīng)譜面積和能量集中程度呈正比,即能量越集中,歸一化譜面積越大,能量分布的越分散,歸一化譜面積越小。速度反應(yīng)效應(yīng)的變化趨勢和速度譜面積相同,二者對(duì)于建筑安全的評(píng)估具有等效性。微差間隔時(shí)間的選擇應(yīng)綜合信號(hào)的振動(dòng)強(qiáng)度、能量在各頻帶的分布、反應(yīng)譜面積和速度反應(yīng)效應(yīng),從能量的角度分析爆破振動(dòng)特征與建筑結(jié)構(gòu)對(duì)外部激勵(lì)響應(yīng)的綜合特性。
[Abstract]:During the construction of subway drilling and blasting in urban subway, the blasting vibration control is strict because the position of rock mass excavation is closer to the ground. The use of electronic detonator makes the exact differential delay a reality. More and more subway blasting uses electronic detonator initiation technology. The electronic detonator blasting can improve the rock breaking effect and reduce the blasting vibration intensity. There is an unparalleled advantage in the field. At present, the theoretical relationship between the delay interval of the blasting and the effect of rock breaking and vibration control has not been established. The field construction relies more on experience and many experiments to determine the delay time of the electronic detonator. It is imminent to study the precise delay of the blasting vibration control of the subway tunnel. Based on the National Natural Science Foundation "study on dynamic response characteristics of cumulative damage of underground structures under ambient pressure environment blasting load (51374212)", the construction of drilling and blasting method for subway tunnels, such as Beijing subway and Shenzhen subway, is taken as the engineering background. The precise delay blasting vibration control of subway tunnel is deeply studied and analyzed. In the field test and numerical calculation, the reasonable delay time delay and intersection delay time are discussed from two aspects of improving the rock breaking effect and reducing the blasting vibration intensity. The influence of the subway tunnel blasting on the adjacent tunnel structure and the ground building is analyzed. The main contents are as follows: (1) based on the existing HHT Methods in the analysis of blasting signal, the corresponding improvement measures are put forward. By calculating the calculation results of the decomposition time, the excessive extremum of different iterations and the correlation coefficients of the IMF components and the original components obtained from different decomposition times, the reasonable total average number of CEEMD is obtained from 200 to 300 times. The determination of the extreme point of the internal endpoint, the data extension of the non stationary signal to the stationary signal in the external data and the extension of the transition segment to the stationary signal extension to the signal endpoint processing of the transition segment stationary phase. The proposed endpoint processing method is embedded in the CEEMD, and the decomposition results of the simulation signal and the actual signal show that the results of the simulation signal and the actual signal are shown. This method preserves the extension trend of the original signal at the end point, reduces the number of iterations and the envelope "undershoot" and "overshoot" from the mutation of the signal caused by the high frequency intermittent noise. The elimination of the extension data can ensure that the original data is not affected by the fluctuation of the endpoint. (2) the solution correlation algorithm is embedded in the CEEMD decomposition. The end point processing method proposed in this paper, the correlation algorithm and the signal joint processing method of CEEMD method, can effectively suppress the signal modal aliasing and avoid the energy loss caused by the false components. The simulation results show that the method has higher resolution than EMD and CEEMD, and the effect of processing the modal aliasing and false components in the signal is better than that of the simulation signal. Well, a good decomposition effect can be obtained through multiple iterations. At the same time, the energy ratio of each IMF signal in the actual signal is low. (3) field test results show that the main frequency of the signal is lower and the main frequency changes with the distance with a large amount of high frequency wave, and it is difficult to pass the tunnel when the depth of the tunnel is large. By setting the difference interval of the electronic detonator to increase the main frequency of blasting, it is necessary to control the blasting vibration intensity by reducing the single hole and the maximum single stage dosage. The three row of cutting holes are used to carry out the blasting construction. From the two aspects of the vibration damping effect and the increase of the driving speed, the blasting is obviously lifted. The setting of the gap between the holes should be comprehensively considered and reduced. The blasting vibration and the improvement of the blasting effect are two factors. The delay interval of the cutting hole is 2ms, the other type of the hole gap is 4ms. Under the premise that the blasting vibration speed is not exceeding the standard, the crushing effect of the surrounding rock is strengthened and the two broken rock probability is reduced. The vibration intensity of the adjacent tunnel is far greater than the back side, because of the platform. The blasting vibration speed of the lower step is less than that of the upper step blasting. The vibration intensity of the tunnel is larger in the 1D range of the front and rear side of the tunnel. The main frequency of the blasting in the tunnel is between 30 and 90hz, which will not cause the resonance of the adjacent tunnel structure, and the damage of the structure is mainly influenced by the vibration velocity. " The safety criterion of speed frequency energy is added to the original safety allowable standard. The new standard is more comprehensive than the previous safety standards. (4) the blasting vibration control and improvement effect of electronic detonator and non electric detonator are analyzed from the angle of three elements and energy of blasting vibration. In the case of the section area of the tunnel, the layout of the gun hole and the number of the holes on the whole, the electronic detonator can be detonated by hole by hole. The blasting vibration intensity is reduced greatly than that of the ordinary millisecond delay detonator and can increase the length of the single blasting. The blasting superposition under different delay time is constructed by the linear superposition method. The stress waveform, when the delay time is in the half cycle of the waveform, the superposition peak vibration speed is obviously reduced, the main frequency of the vibration is promoted in different degrees. The ratio of the energy in the 0 - 20Hz will be greatly reduced. The superposition velocity of the half cycle may not be the minimum peak of the vibration velocity of the synthetic wave. When t/2tt, the superposition of the velocity of vibration increases. The total energy of the millisecond blasting is less than the total energy when the hole is detonated at the same time. The total energy in the half cycle of the waveform and the total energy in the near time range is minimum, and the superimposed energy is greater than the single hole energy. It is proved that it is difficult to control the blasting vibration in the practical application. (5) the effect of rock breaking is improved. The calculation method of the delay between the hole and the interval is considered. The calculation method takes into account the amount of single hole charge, the angle of the hole and the face, the length of the charge, the uncoupling coefficient, the rock mass, the mass and volume of rock mass, the property of the explosive, the depth of the scale and so on. The delay time determined by the precise delay blasting control by using electronic mine pipe must be used. It is not less than the time required to form a new free surface. According to the calculation results, it is finally determined that the delay of the hole in the hole is set to 3 - 4ms; when the auxiliary holes of the inner ring hole and two ring hole are set to 3 - 5ms. to 1.0m, the delay interval of each paragraph is 30ms; when the footage is 1.5m, the slot section is delayed by 45ms and the non cutting section adopts the 40ms extension period. At 2m, the cutting section adopts 50ms large delay interval, and the non cutting section adopts 45ms delay interval. (6) the numerical simulation results of the adjacent tunnel blasting show that the structure of the circular tunnel is less responsive to blasting vibration when the blasting parameters are the same, and the vibration resistance of the horseshoe tunnel is relatively poor. With the increase of the distance between the tunnel and the tunnel, the vibration intensity of the mass point of the attack side appears "fault" attenuation. When the distance is 2.0D, the blasting vibration intensity of each part of the attack side is consistent. At the same time, the cutting hole is the effective dispersed blasting energy of the 6 hole. The blasting vibration strength is reduced, and the blasting vibration intensity is less than 4 hole blasting. When the distance of the tunnel is less than 1.0d, the blasting construction with the single hole dosage of 1.8kg and 2.6kg has great influence on the structure and easily causes the tunnel destruction. The maximum vibration velocity of the three directions is not strictly in the vertical plane parallel to the face of the palm, and the vibration velocity is in the tunnel. The 5m range is oscillatory in the range of the longitudinal direction. (7) a formula for the delay between the adjacent holes in the tunnel is proposed. The reasonable delay time is mainly related to the distance difference between the adjacent cannon holes and the monitoring points, the single hole dosage, the detonating distance and the rock mass property. The effect of the interval is the most, the single hole dosage has the smallest effect on the delay time. The optimal delay time between the holes is different. The calculation results should meet the requirement of the shortest delay time for the formation of the new free surface, that is, not less than 3ms., the same blasting parameters in the circular tunnel are selected at different delay time. The results show that the proportion of the peak and the trough of the adjacent stress wave is larger in the reasonable delay time. The peak vibration speed is reduced and the main frequency of the vibration can be improved. With the increase of the delay time, the load of the explosion stress wave is gradually dispersed in the same position, reducing the superposition probability and peak of the adjacent wave peak and peak. The results of numerical simulation are effectively controlled. The results of the numerical simulation are basically in agreement with the theoretical calculation results. The proposed formula is feasible. The effect of the stress wave is different in different parts of the tunnel. The vibration velocity of the arch shoulder and the help part in the blasting side is much less than that of the hole at the same time. The vibration intensity of the small delay blasting is greater than that of the hole at the same time. Considering the influence of the difference of the hole spacing on the superimposed vibration speed, the minimum delay time of the new free surface and the change of the maximum vibration speed of the tunnel under the different delay are observed. Different tunnels are given for different tunnels under the different distance between the adjacent tunnels. The gap between the holes is 4 holes, and the single hole charge 2.6kg is delayed to 5 - 6ms when the single hole dose is 2.6kg. When the single hole dose is 1.2kg, the hole is delayed to 3 - 5ms; the hole is 6 hole and the single hole dosage is 1.8kg, the interval between the holes is 4 - 6ms. (8). The vibration intensity of the measured waveform of the cut hole blasting under different delay time can be seen, the vibration intensity of the input signal is known. It is the most important factor affecting the area of the response spectrum. The normalized response spectrum area is proportional to the concentration of the energy concentration, that is, the more centralized the energy is, the greater the normalized spectral area, the more dispersed the energy distribution, the smaller the normalized spectral area. The change trend of the velocity response effect is the same as the velocity spectrum area, and the two are equivalent to the assessment of the building safety. The choice of interval time should be the vibration intensity of the integrated signal, the distribution of energy in each frequency band, the response spectrum area and the response effect. The comprehensive characteristics of the blasting vibration characteristics and the external excitation response of the building structure are analyzed from the point of view of the energy.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)(北京)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：U455.6

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