強震區(qū)斷層帶邊坡抗滑樁抗震加固機理及模式研究
發(fā)布時間：2018-08-03 09:05
【摘要】：受“5.12”汶川大地震影響,我國西南山區(qū)發(fā)生了大量邊坡地質(zhì)災害。在強震區(qū)進行公路修建的過程中,邊坡的穩(wěn)定性顯得尤為重要。在這些不同種類的邊坡之中,斷層帶邊坡在地震失穩(wěn)時具有其自身的特點。經(jīng)有關學者研究統(tǒng)計,用抗滑樁加固的斷層帶邊坡在地震作用下只有少數(shù)發(fā)生傾斜變形,大多數(shù)的樁基本無變化,并且其加固的邊坡都比較穩(wěn)定。本文基于以上事實選取廣甘高速公路斷層帶邊坡為研究對象,運用數(shù)值模擬的方法對公路邊坡設計中常用的無平臺、有平臺不同坡高邊坡的動力響應規(guī)律以及抗滑樁加固機理和加固模式進行了研究,并在此基礎上對廣甘高速公路斷層帶邊坡進行了抗滑樁動力穩(wěn)定性分析。通過上述研究獲得的主要成果如下： (1)在地震力作用下,斷層帶邊坡越高,坡體水平位移呈線性增長；坡頂、坡面處水平位移增值較大,坡腳、坡底處較��；最大主應力往坡頂和坡面處集中,當坡高達到一定高度時,坡面形成貫通的拉應力帶,坡腳產(chǎn)生較明顯的應力集中區(qū)域。對比分析認為,斷層帶邊坡高度越高,其動力作用下自穩(wěn)能力越差。記錄地震作用不同時間段坡體的水平位移值情況,結(jié)果發(fā)現(xiàn),在地震波持續(xù)作用下,水平位移值不斷增加,邊坡發(fā)生累積變形。 (2)斷層帶邊坡動力變形分析：由于斷層帶巖體松散、破碎,地震波在邊坡巖土體內(nèi)傳播和作用過程中,坡體內(nèi)產(chǎn)生的橫波和縱波使邊坡巖土體不同部位發(fā)生相互作用,產(chǎn)生拉張或剪切變形甚至導致邊坡巖土體破壞。同時,地震波在傳播過程中遇到界面時將發(fā)生反射、折射現(xiàn)象,不同地震波還將疊加協(xié)同作用,致使巖土體產(chǎn)生拉張變形和剪切變形。 (3)應用FLAC3D軟件模擬支護前后坡體動力響應特征,抗滑樁能顯著改善邊坡坡頂水平位移,約束坡面巖體的變形和破壞；能改善邊坡坡頂與坡腳的塑性區(qū)分布情況,使邊坡應力分布的更加均勻,保證邊坡的穩(wěn)定性。 (4)在地震作用下,記錄了樁間土體以及樁內(nèi)力變化情況。樁頂端要比樁中部變形大,易發(fā)生傾斜破壞。樁剪力在地震作用初期已經(jīng)形成,此后的地震作用只會引起剪力的微小變化。地震作用初期樁彎矩值不大,在零附近波動,隨著地震波持續(xù)作用,彎矩迅速增加到最大值。樁身彎矩變化特征為自下而上先增加后減少,最大值一般位于樁身中間位置附近�？够瑯对O計時,應在內(nèi)力最大值附近增設鋼筋。 (5)對比分析了有無滑面時抗滑樁動力支護效果。邊坡無滑面時樁間土的位移是由坡體內(nèi)部向臨空面逐漸增加,坡體塑性變形區(qū)集中在坡面處,坡頂有少部分變形,樁身所受內(nèi)力值較�。挥谢鏁r樁間土的位移由坡體內(nèi)部向臨空面先增大后減小,邊坡覆蓋層土體變形很大,在坡頂處存在大量的塑性變形區(qū),邊坡土體較容易沿著滑面往臨空面方向移動,抗滑樁內(nèi)力值較大,易發(fā)生破壞。值得注意的是,邊坡具有滑面時能顯著影響樁間土體位移變化情況,在滑面處位移最大。 (6)總結(jié)出了抗滑樁對強震區(qū)斷層帶邊坡的加固機理：斷層帶巖體松散、破碎,地震波作用在坡體上產(chǎn)生振蕩效應,使巖體在反復的振蕩過程中產(chǎn)生松弛進而向臨空面滑動。當抗滑樁支護后,它具有擠密作用,改善樁周巖土體；當?shù)卣鸩ㄖ械拿娌◤钠麦w傳播到抗滑樁界面時,一部分直接傳播在樁身處,另一部分傳播在樁土間壓力拱處,由壓力拱將地震波傳播于抗滑樁；地震波中的縱波與橫波傳播到樁附近時,由于抗滑樁比斷層帶巖體彈性好,能量損失較少,波經(jīng)過反射之后反而對坡體產(chǎn)生了加固作用。與此同時,樁身剪力最大值一般位于坡體較易滑出位置與樁身相交處,樁兩端點所受剪力與中間點的剪力反向；樁身彎矩一般在錨固段以下2m-3m左右處最大,呈對稱分布。剪力與彎矩都是隨著地震波作用先增大再減小最后增大達到最大值。 (7)對比分析了懸臂樁與全埋樁,樁錨固長度8m、10m和12m,樁間距5-10m時坡體動力變化情況,模型坡高30m(分三級放坡,每級10m)、坡比1：1時抗滑樁具有以下規(guī)律：①懸臂樁能改善坡體整體變形值,降低樁后動土壓力值；全埋樁樁身內(nèi)力較小,耗材少,降低工程造價；②抗滑樁錨固段長10m和12m要比長8m加固效果好；③樁間距9m和10m時坡體已經(jīng)產(chǎn)生了大變形,說明邊坡已發(fā)生破壞,這兩種樁間距對邊坡加固效果不好。
[Abstract]:Influenced by the "5.12" Wenchuan earthquake, a large number of slope geological disasters have occurred in the southwestern mountainous areas of China. In the process of highway construction in the strong earthquake area, the stability of the slope appears particularly important. In these different kinds of slopes, the slope of the fault zone has its own characteristics when the earthquake is unstable. The slope of the fault zone reinforced by pile is only a few inclined deformation under the earthquake action, most of the piles are basically unchanged, and the reinforced slope is relatively stable. Based on the above facts, this paper selects the slope of the Guangzhou Gansu highway fault zone as the research object, and uses the numerical simulation method to do no platform in the highway slope design. The dynamic response law of the slope with different slope and high slope, the reinforcement mechanism and the strengthening mode of the anti slide pile are studied. On this basis, the dynamic stability of the anti slide pile of the Guangzhou Gansu highway fault zone slope is analyzed. The main achievements obtained through the above study are as follows:
(1) the higher the slope of the fault zone, the higher the slope of the slope, the higher the horizontal displacement of the slope, the high increment of the horizontal displacement at the slope, the lower of the slope foot and the bottom of the slope; the maximum main stress is concentrated on the slope top and the slope. When the slope is up to a certain height, the slope surface forms the tensile stress zone which is connected with the slope, and the slope foot produces a more obvious stress concentration area. It is found that the higher the height of the slope of the fault zone is, the worse the self stability under the dynamic action. The horizontal displacement of the slope in different periods of earthquake action is recorded. It is found that the horizontal displacement value increases continuously under the continuous action of the seismic wave, and the cumulative deformation of the slope occurs.
(2) analysis of dynamic deformation of slope of fault zone: due to the loose and broken rock mass of the fault zone, during the propagation and action of the seismic wave in the rock and soil of the slope, the transverse waves and the longitudinal waves produced by the slope cause the interaction between the different parts of the rock and soil of the slope, and the tensile or shear deformation causes the failure of the slope and soil mass. At the same time, the seismic wave is propagating. Reflection and refraction will occur when the interface is encountered, and different seismic waves will superimpose synergistic effect, resulting in tensile deformation and shear deformation of rock and soil.
(3) using FLAC3D software to simulate the dynamic response characteristics of slope body before and after supporting, the anti slide pile can significantly improve the horizontal displacement of the slope top, restrain the deformation and damage of the rock slope, improve the distribution of the plastic zone of the slope top and the foot of the slope, make the distribution of the slope stress more uniform and ensure the stability of the slope.
(4) under the action of earthquake, the change of soil and internal force between piles is recorded. The pile tip is larger than the middle part of the pile, and it is prone to collapse. The pile shear force has been formed in the early stage of the earthquake action, and the earthquake action will only cause small changes in the shear force. The bending moment of the pile increases quickly to the maximum. The change of the bending moment of the pile body is first increased and then decreased from bottom to top. The maximum value is usually located near the middle position of the pile. When the anti slide pile is designed, the reinforcement should be added near the maximum internal force.
(5) the dynamic support effect of the anti slide pile is compared and analyzed. The displacement of the soil between the piles without sliding surface is gradually increased from the interior of the slope to the facing surface, the plastic deformation area of the slope is concentrated on the slope, the top of the slope is small and the internal force of the pile is small, and the displacement of the soil between the piles is increased from the interior of the slope to the air surface. A large number of plastic deformation zones exist at the top of the slope at the top of the slope. It is easy to move along the slip surface to the surface of the surface, and the internal force of the anti slide pile is large and easy to destroy. It is worth noting that the displacement of the soil between the piles can be significantly changed when the slope has a sliding surface, and the displacement is maximum in the sliding surface.
(6) the reinforcement mechanism of the anti slide pile to the slope of the fault zone in strong earthquake zone is summarized. The rock mass is loose and broken, and the vibration effect of the seismic wave is produced on the slope body, so that the rock mass is relaxed and then slips to the air surface during the repeated oscillation. When the anti slide pile is supported, it has the effect of compaction, the improvement of the pile surrounding rock mass, and the seismic wave. When the surface wave propagates from the slope body to the anti slide pile interface, a part of the wave propagates directly in the pile body, the other is propagated at the pressure arch between the pile and soil, and the seismic wave is propagated by the pressure arch to the anti slide pile. When the longitudinal wave and the shear wave propagate to the pile, the anti slide pile is better than the fault belt, and the energy loss is less and the wave passes through the reverse. At the same time, the maximum shear strength of the pile body is generally located at the intersection of the slope and the pile body. The shear strength of the two ends of the pile is opposite to the middle point. The bending moment of the pile body is the largest and symmetrical distribution at about 2m-3m below the anchorage section. The shear and bending moment are all along with the seismic waves. The effect increases first and then decreases and finally increases to the maximum.
(7) comparing and analyzing the dynamic changes of the slope body of the cantilever pile and all pile, pile anchor length 8m, 10m and 12M, the pile spacing of 5-10m, the model slope is 30m (three grade, each level), and the slope ratio 1:1 has the following rules: (1) the cantilever pile can improve the whole deformation value of the slope and reduce the value of the soil pressure after the pile; the internal force of the whole pile pile is small, The cost of the material is less and the cost of the project is reduced; (2) the length of 10m and 12m of the anchorage section of anti slide pile is better than that of the long 8m. 3. When the pile spacing is 9m and 10m, the slope has produced large deformation, which indicates that the slope has been damaged, and the two pile spacing is not good for the slope reinforcement.
【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U418.52
本文編號：2161268
[Abstract]:Influenced by the "5.12" Wenchuan earthquake, a large number of slope geological disasters have occurred in the southwestern mountainous areas of China. In the process of highway construction in the strong earthquake area, the stability of the slope appears particularly important. In these different kinds of slopes, the slope of the fault zone has its own characteristics when the earthquake is unstable. The slope of the fault zone reinforced by pile is only a few inclined deformation under the earthquake action, most of the piles are basically unchanged, and the reinforced slope is relatively stable. Based on the above facts, this paper selects the slope of the Guangzhou Gansu highway fault zone as the research object, and uses the numerical simulation method to do no platform in the highway slope design. The dynamic response law of the slope with different slope and high slope, the reinforcement mechanism and the strengthening mode of the anti slide pile are studied. On this basis, the dynamic stability of the anti slide pile of the Guangzhou Gansu highway fault zone slope is analyzed. The main achievements obtained through the above study are as follows:
(1) the higher the slope of the fault zone, the higher the slope of the slope, the higher the horizontal displacement of the slope, the high increment of the horizontal displacement at the slope, the lower of the slope foot and the bottom of the slope; the maximum main stress is concentrated on the slope top and the slope. When the slope is up to a certain height, the slope surface forms the tensile stress zone which is connected with the slope, and the slope foot produces a more obvious stress concentration area. It is found that the higher the height of the slope of the fault zone is, the worse the self stability under the dynamic action. The horizontal displacement of the slope in different periods of earthquake action is recorded. It is found that the horizontal displacement value increases continuously under the continuous action of the seismic wave, and the cumulative deformation of the slope occurs.
(2) analysis of dynamic deformation of slope of fault zone: due to the loose and broken rock mass of the fault zone, during the propagation and action of the seismic wave in the rock and soil of the slope, the transverse waves and the longitudinal waves produced by the slope cause the interaction between the different parts of the rock and soil of the slope, and the tensile or shear deformation causes the failure of the slope and soil mass. At the same time, the seismic wave is propagating. Reflection and refraction will occur when the interface is encountered, and different seismic waves will superimpose synergistic effect, resulting in tensile deformation and shear deformation of rock and soil.
(3) using FLAC3D software to simulate the dynamic response characteristics of slope body before and after supporting, the anti slide pile can significantly improve the horizontal displacement of the slope top, restrain the deformation and damage of the rock slope, improve the distribution of the plastic zone of the slope top and the foot of the slope, make the distribution of the slope stress more uniform and ensure the stability of the slope.
(4) under the action of earthquake, the change of soil and internal force between piles is recorded. The pile tip is larger than the middle part of the pile, and it is prone to collapse. The pile shear force has been formed in the early stage of the earthquake action, and the earthquake action will only cause small changes in the shear force. The bending moment of the pile increases quickly to the maximum. The change of the bending moment of the pile body is first increased and then decreased from bottom to top. The maximum value is usually located near the middle position of the pile. When the anti slide pile is designed, the reinforcement should be added near the maximum internal force.
(5) the dynamic support effect of the anti slide pile is compared and analyzed. The displacement of the soil between the piles without sliding surface is gradually increased from the interior of the slope to the facing surface, the plastic deformation area of the slope is concentrated on the slope, the top of the slope is small and the internal force of the pile is small, and the displacement of the soil between the piles is increased from the interior of the slope to the air surface. A large number of plastic deformation zones exist at the top of the slope at the top of the slope. It is easy to move along the slip surface to the surface of the surface, and the internal force of the anti slide pile is large and easy to destroy. It is worth noting that the displacement of the soil between the piles can be significantly changed when the slope has a sliding surface, and the displacement is maximum in the sliding surface.
(6) the reinforcement mechanism of the anti slide pile to the slope of the fault zone in strong earthquake zone is summarized. The rock mass is loose and broken, and the vibration effect of the seismic wave is produced on the slope body, so that the rock mass is relaxed and then slips to the air surface during the repeated oscillation. When the anti slide pile is supported, it has the effect of compaction, the improvement of the pile surrounding rock mass, and the seismic wave. When the surface wave propagates from the slope body to the anti slide pile interface, a part of the wave propagates directly in the pile body, the other is propagated at the pressure arch between the pile and soil, and the seismic wave is propagated by the pressure arch to the anti slide pile. When the longitudinal wave and the shear wave propagate to the pile, the anti slide pile is better than the fault belt, and the energy loss is less and the wave passes through the reverse. At the same time, the maximum shear strength of the pile body is generally located at the intersection of the slope and the pile body. The shear strength of the two ends of the pile is opposite to the middle point. The bending moment of the pile body is the largest and symmetrical distribution at about 2m-3m below the anchorage section. The shear and bending moment are all along with the seismic waves. The effect increases first and then decreases and finally increases to the maximum.
(7) comparing and analyzing the dynamic changes of the slope body of the cantilever pile and all pile, pile anchor length 8m, 10m and 12M, the pile spacing of 5-10m, the model slope is 30m (three grade, each level), and the slope ratio 1:1 has the following rules: (1) the cantilever pile can improve the whole deformation value of the slope and reduce the value of the soil pressure after the pile; the internal force of the whole pile pile is small, The cost of the material is less and the cost of the project is reduced; (2) the length of 10m and 12m of the anchorage section of anti slide pile is better than that of the long 8m. 3. When the pile spacing is 9m and 10m, the slope has produced large deformation, which indicates that the slope has been damaged, and the two pile spacing is not good for the slope reinforcement.
【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U418.52
【參考文獻】
相關期刊論文 前10條
1 梁青槐;土-結(jié)構(gòu)動力相互作用數(shù)值分析方法的評述[J];北方交通大學學報;1997年06期
2 羅渝;何思明;何盡川;;地震作用下抗滑樁作用機制研究[J];長江科學院院報;2010年06期
3 溫瑞智,周正華,孫平善,楊柏坡,李山有;斷層場地地震動分析[J];地震工程與工程振動;2002年01期
4 肖曉春,遲世春,林皋,約翰·艾法羅;地震荷載下樁土相互作用簡化計算方法及參數(shù)分析[J];大連理工大學學報;2002年06期
5 劉向峰,王來貴;非發(fā)震斷層場地地震動力響應特性研究[J];遼寧工程技術大學學報;2005年01期
6 丁偉農(nóng),高明;非線性土體樁土相互作用對高樁碼頭抗震設計影響的分析[J];港工技術;1996年04期
7 衣偉;考慮樁上相互作用高樁碼頭單樁地震反應[J];港口工程;1997年04期
8 孫峰;孔紀名;蔡強;阿發(fā)友;崔云;;在地震作用下碎石土滑坡抗滑樁的抗震加固作用機理研究[J];工業(yè)安全與環(huán)保;2012年08期
9 汪鵬程;朱大勇;許強;;強震作用下加固邊坡的動力響應及不同加固方式的比較研究[J];合肥工業(yè)大學學報(自然科學版);2009年10期
10 劉革新;王劍;;抗滑樁的研究進展[J];湖南城市學院學報(自然科學版);2007年04期
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