• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Brillouin optical time-domain analysis for geotechnical monitoring

    2015-02-09 01:29:00ZeniPirelliAvolioCosettPpZeniDiMioVsslloMinro

    L.Zeni,L.Pirelli,B.Avolio,A.Cosett,R.Pp,G.Zeni,C.Di Mio, R.Vssllo,A.Minro

    aDIII,Second University of Naples,Aversa,Italy

    bInstitute for Electromagnetic Sensing of the Environment(IREA),National Research Council,Napoli,Italy

    cDICDEA,Second University of Naples,Aversa,Italy

    dSchool of Engineering,University of Basilicata,Potenza,Italy

    Brillouin optical time-domain analysis for geotechnical monitoring

    L.Zenia,b,*,L.Picarellic,B.Avolioc,A.Coscettaa,R.Papac,G.Zenib,C.Di Maiod, R.Vassallod,A.Minardoa

    aDIII,Second University of Naples,Aversa,Italy

    bInstitute for Electromagnetic Sensing of the Environment(IREA),National Research Council,Napoli,Italy

    cDICDEA,Second University of Naples,Aversa,Italy

    dSchool of Engineering,University of Basilicata,Potenza,Italy

    A R T I C L EI N F O

    Article history:

    Received 30 November 2014

    Received in revised form

    8 January 2015

    Accepted 26 January 2015

    Available online 9 May 2015

    Brillouin optical time-domain analysis

    (BOTDA)

    Tunnel engineering

    Deformation

    Distributed monitoring

    Health diagnosis

    In this paper,we show some recent experimental applications of Brillouin optical time-domain analysis (BOTDA)based sensors for geotechnical monitoring.In particular,how these sensors can be applied to detecting early movements of soil slopes by the direct embedding of suitable fber cables in the ground is presented.Furthermore,the same technology can be used to realize innovative inclinometers,as well as smart foundation anchors.

    ?2015 Institute of Rock and Soil Mechanics,Chinese Academy of Sciences.Production and hosting by Elsevier B.V.All rights reserved.

    1.Introduction

    Distributed fber-optic strain sensors have great potentialities in the feld of geotechnical monitoring(Dewynter et al.,2009; Olivares et al.,2009;Iten,2011;Minardo et al.,2014).By integrating a single fber-optic cable into soil or a geotechnical work,a large number of accurate,spatially resolved data can be obtained. The Brillouin optical time-domain analysis(BOTDA)method allows for strain measurements in the microstrain range,with a typical spatial resolution of 1 m and a maximum sensing range of 50 km. This means that thousands of“strain gauges”along a single cable connected to structures,embedded in soil or grouted into boreholes,for example,can provide information about the current state of the object under supervision.The objects can include geological and civil structures,such as a construction site,a tunnel,a landslide prone area,or a pipeline.It is evident that such a technology implies a beneft for placing fber-optic cables anywhere possible on construction sites and in the green feld(Minardo et al.,2012).

    This paper summarizes some results of experiments carried out byresearch staff at Second University of Naples.Inparticular,aftera brief description of the sensor technology,three applications of the BOTDA technology in the geotechnical feld will be described:(a) slope monitoring by optical fbers embedded into the soil;(b) detection of soil movement by use of an optical fber based inclinometer;(c)monitoring of a ground anchor by use of an embedded optical fber.

    2.Principle of operation of BOTDA

    The experimental results reported in this paper have been conducted exploiting stimulated Brillouin scattering(Boyd,2008)in single-mode optical fbers.In brief,two counter-propagating lightwaves exchange energy along the fber,in a measure depending on their frequency offset.If the offset falls within a specifc range,the radiation at higher frequency(pump wave)transfers energy to that at lower frequency(Stokes wave).The sensing principle is based on the fact that the frequency difference at which the maximum amplifcation of the Stokes wave occurs,known as Brillouin frequencyshift(BFS),variesdependingonthemechanicalandthermal states of the fber.In particular,the BFS increases with both temperature and strain.Spatial resolution,i.e.the ability to measure deformation and temperature changes in a distributed way,can be achieved through the use of a pulsed pump beam:in this way,the interaction takes place along successive sections of the fber as the pump pulse propagates down the sensing cable.By recording the intensity of the Stokes radiation as a function of time,the Brillouin gaincanbetracedineachsection.Themeasurementof theBrillouin gain as a function of time and frequency allows the entire profle ofBrillouin shift along the fber to be obtained,which in turn can be translated in terms of deformation or temperature through the use of appropriate calibration coeffcients.

    Fig.1 shows the basic confguration employed for BOTDA.The pulsed and continuous wave(CW)beams are generated by two separated sources having lasing frequenciesν0andν0±νB,shifted by a defnite quantity in the range of the Brillouin frequency shift of the sensing fber.Fig.1 shows that the amplifcation of the Stokes beam occurs at those locations where the frequency offset with the crossing pulse matches the local Brillouin frequency shift,which in turn is related to the temperature(or strain)of the analyzed fber coil.More in general,Brillouin time-domain signals are acquired in BOTDA systems for a range of frequency offsets,so as to get a full picture of the Brillouin frequency shift at each location.

    Fig.1.Basic confguration for BOTDA:(a),(b)and(c)show the waveform of optical power at detector(Pd),acquired when the frequency offset between the two lasers is tuned to the Brillouin frequency shiftνBof fber coils 1,2 and 3,placed at temperaturesT1,T2andT3,respectively.

    3.Experiments on small-scale model slopes

    The main requirements of monitoring systems in areas susceptible to sudden and rapid landslides should be the following:(a) a cheap and reliable instrumentation;(b)continuous monitoring in time and space;(c)low probability of error to avoid false or missed alarms.

    For their ability to measure strainwith spatial continuity,optical fbers are particularly attractive.For this reason,we decided to check their performance in the monitoring of slopes in loose unsaturated granular soils susceptible to catastrophic rainfall-induced fowslides.The basic idea is that a sensing fber buried in the soil can detect the deformation due to ongoing volumetric and/or shear strains induced by the decrease in suction,which can be interpreted as a warning of incoming failure.The capability of the fber to provide distributed strain readings should allow to detect ongoing deformation at any point of even very long slope sections. This is a fundamental advantage with respect to conventional monitoring devices(topographic readings,inclinometers,etc.) which can provide information only at specifc points.The low cost of fbers is another relevant advantage.

    This simple idea suggested an experimental program to test this new kind of sensors in small-scale model slopes subjected to artifcial rainfall.The slopes are made of volcanic ash laid down into a fume imposing the same porosity as in the feld.The water infltration induced by artifcial rain causes an increase in the water content and a decrease in suction and,consequently,volumetric and shear strains;this mechanical process can lead to slope failure. The basic equipment for monitoring includes tensiometers,pore pressure transducers,laser displacement transducers,electrical moisture probes(TDRs)and video-cameras(see Fig.2).For the present application the fume was tilted with an inclination of 40°, and equipped with tensiometers,displacement sensors and optical fbers.The latter was a tight-buffer standard single-mode fber for telecommunications having an overall diameter of 900μm.The optical fber sensor was buried into the ground along two alignments parallel to each other(Fig.2).The model slopes,as a proof of principle,have been made up with volcanic ashes taken from the site of Cervinara,Italy,where feld monitoring is being carried out (Pirone et al.,2012).The slope has a length of 1.35 m,thickness of 10 cm,initial water content ranging between 43%and 50%,and porosity close to the feld value(70%-76%).

    In the experiment,a system of anchoring constituted by small plastic grids glued every 20 cm at the fber was adopted,as shownin Fig.3a.Fig.3b shows the position of the tensiometers and of the laser displacement sensors.

    Fig.2.The instrumented fume.

    The readings of the optical fber sensorare reported in Fig.4.The increase in Brillouin frequency shift from the initial profle(t=0), which reveals a state of stress due to accumulated strains during a frst test stage not reported here,to the latest one(t=47 min),is about 200 MHz.This corresponds to a deformation of about 0.4%. The collapse of the slope occurs after 50 min.Readings recorded after failure(t>tf)show that the Brillouin frequency shift returns to its initial value.

    For the sake of comparison,the readings of the tensiometers and displacement sensors are reported in Figs.5a and b,respectively.As it can be seen from Fig.5,the soil is completely saturated at surface before any settlement begins,while the saturation of the deep layer is complete only when a vertical displacement of the soil of a few millimeters is recorded.On the other hand,the optical fber sensors,being deployed in order to detect the soil sliding,start measuring a signifcant tensile strain when the early signs of the slope sliding occur.

    Fig.3.(a)Sensing fber anchored to the soil deposit.(b)Position of the tensiometers (T)and displacement sensors(L).

    4.Optical fber inclinometer

    An inclinometer based on BOTDA has been devised and realized. Its main characteristics can be summarized as follows:(a)measurement of three-dimensional(3D)deformation of soil;(b) continuous monitoring from a remote site and multiplexing capability;(c)self-compensation against temperature variations;(d) displacement sensitivity as high as 1 mm over 1 m;(e)safe operation up to overall displacements as large as 15 cm over 1 m,the limit being posed just by the breaking of the sensing optical fber.

    It should be emphasized that the above characteristics are not fulflled by traditional inclinometers which usually require periodic inspections for interrogation,and become useless if the displacement reaches values as large as to prevent the sliding of the measuring head along the inclinometer tube itself(a few centimeters of movement across a narrow slip plane).

    The optical fber inclinometer is realized by epoxy-gluing four equally spaced fbers along the surface of a PVC pipe for its entire length,as shown in Fig.6.

    The pipe is 50 mm in diameter,and 3.2 mm in thickness,while its overall length is 750 cm,achieved by connecting three pipe sections of 250 cm.The measurement of the strain profles along the fbers allows the reconstruction of the 3D deformation of the pipe and,consequently,the movements of the soil wherethe pipe is embedded(Lenke et al.,2011).

    In order to assess the validity of the proposed approach,several laboratory tests were performed on the inclinometer tube before on-site installation.Fig.7a shows the selection of the results achieved during the laboratory tests.In detail,we show the vertical displacement along a 180 cm-long pipe,with identical crosssection of the pipe used on-site,subjected to prescribed displacement at one end and fxed on the other end.The displacements retrieved by the optical fber sensor using a Brillouin shift sensitivity to strain of 417 MHz/%and a spatial resolution of 20 cm,are compared to the ones provided by eight dial gauges distributed along the pipe.It is seen that the agreement is remarkably good.In particular,the maximum deviation between the dial gauge and optical fber displacement was about 4 mm,while the standard deviation of the measurement error was about 1 mm.Note that the observed discrepancy is coherent with an error analysis of the displacement.In fact,assuming a strain uncertaintyσε=100με,we can calculate the standard deviation of the displacement simply bywhereLandDrepresentthe pipe length and diameter,respectively; Δzis the spatial resolution.This equation shows that the variance of displacement grows with the pipe length,thus the proposed method may suffer from inaccuracies for relatively long pipes.

    Fig.4.Temporal sequences of the Brillouin shift along the fber.

    Fig.5.(a)Suctionua-uw,whereuaanduware the air pressure and the pore water pressure,respectively.(b)Vertical displacementuz.

    In regard to on-site measurement results,the selected test site was an area,located in Basilicata Region,Italy,subjected to slowsoil movements and already instrumented with traditional inclinometer tubes.The test site is depicted in Fig.8,where the positions of the traditional inclinometers and the fber optic one are shown,as well.

    The optical fber inclinometer was installed in a 750 cm deep borehole which was then flled with grout.After allowing the grout cure for one month,a frst measurement was performed as a reference in order to eliminate all the strain induced by the installation procedure.

    The subsequent measurements allow the detection of any soil movements.Fig.9 shows the obtained results.Despite its limited length,the fber optical inclinometer exhibits a suffcient accuracy in detecting the maximum pipe displacement at the ground surface.

    Fig.6.The optical fber inclinometer tube.

    5.A“smart”foundation anchor

    For this experiment,a smart foundation anchor was devised and realized.The main objective of this activity was to improve the understanding of the anchor’s load bearing behavior,as the performance of the anchor is limited by the effciency of load transfer from the anchor tendon to the soil via the grout(Iten, 2011).

    In brief,the anchor was equipped with an optical fber epoxyglued inside the steel tendon.The optical fber was disposed in a loop confguration so as to have both ends available for BOTDA distributed strain measurements.A special optical fber cable with 3.2 mm outer diameter,produced by Brugg Kabel AG,was selected for the tests(V1 cable).

    After realization,the anchor was feld-installed in Campania Region,Italy.Distributed strain measurements were taken at each loading step.The results are summarized in Figs.10 and 11.Note that the symmetrical appearance of the various strain profles is due to the fact that the same fber was running twice along the cable.We observe a number of signifcant features:(a)the strain decreases linearly from the ground level,vanishing at the deepest end of the cable:this means that the whole cable length is involved in transferring the pullout force into the soil;(b)at larger displacement steps,the strain profle propagates behind the fxationpoint due toslippage of the glass fber inside the protection;(c) comparing Figs.10 and 11,it is seen that there is a signifcant residual strain along the fber at the end of the pullout test:for example,during the unloading phase a load of 100 kN produces a maximum strain of about 1000με,equivalent to the strain observed during the loading phase for a load of 350 kN.

    Fig.8.Test site in Basilicata Region,Italy.S9F:fber optic inclinometer;I9B,I9C: traditional inclinometers.

    Fig.7.Comparison between the displacements provided by the optical fber sensor (solid lines)and the ones provided by the dial gauges(squares).δrepresents the maximum displacement applied at the free end.

    6.Conclusions

    Fig.9.Displacement of the optical fber inclinometer(FOI-S9F)as a function of depth, and comparison with the readings of two traditional inclinometers:the I9B(depth: 27 m)and the I9C(depth:15 m)(after Minardo et al.,2014).

    Different applications of BOTDA based optical fber distributed sensors to geotechnical monitoring have been reported.Laboratoryand feld tests have shown the great potentialities of such sensors in monitoring and analyzing soil slopes and foundations.The main limitations of the proposed technology in geotechnical monitoring are essentially the lack of standardized procedures for sensing cables installation in large areas,the diffculty in data interpretation and accurate modeling of ground/sensor interaction.

    Fig.10.Strain measurements during the loading phase.

    Fig.11.Strain measurements during the unloading phase.

    Confict of interest

    The authors wish to confrm that there are no known conficts of interest associated with this publication and there has been no signifcant fnancial support for this work that could have infuenced its outcome.

    Acknowledgments

    It is gratefully noted that the project is supported by grant from MIUR-PON01 1525-MONICA.

    Boyd RW.Nonlinear optics.3rd ed.Waltham,Massachusetts,USA:Academic Press; 2008.

    Dewynter V,Rougeault S,Magne S,Ferdinand P,Vallon F,Avallone L,Vacher E,De Broissia M,Ch Canepa,Poulain A.Brillouin optical fber distributed sensor for settlement monitoring while tunneling the metro line 3 in Cairo,Egypt.In: Proceedings of the SPIE 7503,20th International Conference on Optical Fibre Sensors,75035M;2009.http://dx.doi.org/10.1117/12.835376.

    Iten M.Novel applications of distributed fber-optic sensing in geotechnical engineering.Zurich,Switzerland:vdf Hochschulverlag AG;2011.

    Lenke P,Wendt M,Krebber K,Gl?tzl R.Highly sensitive fber optic inclinometer: easy to transport and easy to install.In:Proceedings of the SPIE 7753,21st International Conference on Optical Fiber Sensors,775352;2011.http:// dx.doi.org/10.1117/12.884695.

    Minardo A,Bernini R,Amato L,Zeni L.Bridge monitoring using Brillouin fber-optic sensors.IEEE Sensor Journal 2012;12(1):145-50.

    Minardo A,Picarelli L,Avolio B,Coscetta A,Papa R,Zeni G,Di Maio C,Vassallo R, Zeni L.Fiber optic based inclinometer for remote monitoring of landslides:on site comparison with traditional inclinometers.In:Proceedings of International Geoscience and Remote Sensing Symposium(IGARSS 2014)/35th Canadian Symposium on Remote Sensing(35th CSRS),Québec City,Québec,Canada; 2014.p.4078-81.

    Olivares L,Damiano E,Picarelli L,Greco R,Bernini R,Minardo A,Zeni L.An instrumented fume for investigation of the mechanics of rainfall-induced landslidesinunsaturatedgranularsoils.GeotechnicalTestingJournal 2009;32(2):108-18.

    Pirone M,Damiano E,Picarelli L,Olivares L,Urciuoli G.Groundwater-atmosphere interaction in unsaturated pyroclastic slopes at two sites in Italy.Rivista Italiana di Geotecnica 2012;3:29-49.

    Luigi Zeniis full professor of electronics and photonics at the Second University of Naples and president of the Research Consortium on Advanced Remote Sensing Systems-CO.RI.S.T.A.(www.corista.eu).He has been,from 2001 to 2012,vice-director of the Department of Information Engineering.He took his degree in Electronic Engineering,summa cum laude,from University of Naples in 1988 and his Ph.D.in Electronics and Computer Science in 1992.He worked at TU-DELFT(NL)as a visiting scientist. He has been national coordinator of PRIN projects,scientifc coordinator of research contracts with public and private institutions and responsible for projects funded within the 7th FP of the EU.He has been member of the Management Committee of the COST 299“Optical fbers for new challenges facing the information society”and of the COST TD1001“Novel and Reliable Optical Fiber Sensor Systems for Future Security and Safety Applications”. His main research interests include optical fber sensors for distributed measurements of deformation and temperature,optoelectronic integrated sensors and biosensors.He is author of about 120 papers published in international journals,120 publications at international conferences and 10 patents.He is also founder of the Spin-Off company OPTOSENSING dealing with structural and environmental monitoring by optical fber sensors.

    *Corresponding author.Tel.:+39 0815010269.

    E-mail address:luigi.zeni@unina2.it(L.Zeni).

    Peer review under responsibility of Institute of Rock and Soil Mechanics,Chinese Academy of Sciences.

    1674-7755?2015 Institute of Rock and Soil Mechanics,Chinese Academy of Sciences.Production and hosting by Elsevier B.V.All rights reserved.

    http://dx.doi.org/10.1016/j.jrmge.2015.01.008

    欧美xxxx性猛交bbbb| 日韩强制内射视频| 久久综合国产亚洲精品| 少妇人妻精品综合一区二区 | 亚洲av不卡在线观看| 欧美最黄视频在线播放免费| 免费看光身美女| 国产免费一级a男人的天堂| 久久精品国产亚洲av香蕉五月| 欧美日韩乱码在线| 三级毛片av免费| 国产在线精品亚洲第一网站| 国产精品亚洲一级av第二区| av免费在线看不卡| 女人十人毛片免费观看3o分钟| 有码 亚洲区| 日本三级黄在线观看| 精品免费久久久久久久清纯| 日韩欧美三级三区| 亚洲内射少妇av| 综合色av麻豆| 欧美激情在线99| 嫩草影院入口| 亚洲av免费高清在线观看| 桃色一区二区三区在线观看| 干丝袜人妻中文字幕| 丝袜喷水一区| 97超碰精品成人国产| 国产av一区在线观看免费| 欧美一级a爱片免费观看看| 男人狂女人下面高潮的视频| 日韩亚洲欧美综合| 美女xxoo啪啪120秒动态图| 精品久久久久久久久av| 欧美性猛交╳xxx乱大交人| 黑人高潮一二区| 亚洲真实伦在线观看| 18+在线观看网站| 联通29元200g的流量卡| 成人一区二区视频在线观看| 日韩在线高清观看一区二区三区| 天天一区二区日本电影三级| 白带黄色成豆腐渣| 国产黄色小视频在线观看| 校园人妻丝袜中文字幕| 一级毛片我不卡| 最近2019中文字幕mv第一页| 国产精品久久久久久av不卡| 别揉我奶头 嗯啊视频| 久久九九热精品免费| 色综合站精品国产| 免费不卡的大黄色大毛片视频在线观看 | 成人特级av手机在线观看| 国产蜜桃级精品一区二区三区| 最好的美女福利视频网| 亚洲真实伦在线观看| 国内揄拍国产精品人妻在线| 露出奶头的视频| 亚洲欧美中文字幕日韩二区| 天堂网av新在线| 国产极品精品免费视频能看的| 热99在线观看视频| 97热精品久久久久久| 特大巨黑吊av在线直播| av专区在线播放| 99久久成人亚洲精品观看| 成人鲁丝片一二三区免费| 成人二区视频| 久久久久久久久久久丰满| 一个人看的www免费观看视频| 色噜噜av男人的天堂激情| 丝袜美腿在线中文| 国产综合懂色| 国产爱豆传媒在线观看| 黄色视频,在线免费观看| 国产精品一二三区在线看| 搡老熟女国产l中国老女人| 人人妻人人澡欧美一区二区| 99久久无色码亚洲精品果冻| 最近最新中文字幕大全电影3| 午夜视频国产福利| 看非洲黑人一级黄片| 成人精品一区二区免费| 成人永久免费在线观看视频| 91午夜精品亚洲一区二区三区| 一级毛片电影观看 | 亚洲乱码一区二区免费版| 99九九线精品视频在线观看视频| 99热这里只有精品一区| 午夜福利在线观看免费完整高清在 | 国产精品人妻久久久影院| 毛片女人毛片| 国产色婷婷99| 天天躁夜夜躁狠狠久久av| 男女视频在线观看网站免费| 国内久久婷婷六月综合欲色啪| 欧美日韩综合久久久久久| 99久久精品热视频| 国产精品美女特级片免费视频播放器| 国产精品99久久久久久久久| 精品一区二区免费观看| 精品欧美国产一区二区三| 99精品在免费线老司机午夜| 亚洲自拍偷在线| 日日干狠狠操夜夜爽| 午夜精品国产一区二区电影 | 寂寞人妻少妇视频99o| 国产黄a三级三级三级人| 最近2019中文字幕mv第一页| 久久精品国产亚洲av涩爱 | 夜夜爽天天搞| 欧美最黄视频在线播放免费| 美女免费视频网站| 97热精品久久久久久| 国产成人a区在线观看| 一区二区三区高清视频在线| 校园人妻丝袜中文字幕| 欧美高清性xxxxhd video| 精品不卡国产一区二区三区| 国产精品日韩av在线免费观看| 久久人人爽人人片av| 国产免费男女视频| 久久中文看片网| 最近在线观看免费完整版| 亚洲av中文字字幕乱码综合| eeuss影院久久| 精品久久久久久久末码| 真人做人爱边吃奶动态| 日本 av在线| 久久久久九九精品影院| 亚洲成av人片在线播放无| 最好的美女福利视频网| 久久久久九九精品影院| 啦啦啦韩国在线观看视频| 日韩精品青青久久久久久| 日本免费a在线| 亚洲美女搞黄在线观看 | 久久精品国产亚洲网站| 欧美日韩综合久久久久久| 十八禁网站免费在线| 韩国av在线不卡| 天天一区二区日本电影三级| 国产欧美日韩精品亚洲av| 麻豆乱淫一区二区| 在线观看免费视频日本深夜| 亚洲性夜色夜夜综合| 人妻久久中文字幕网| 精品不卡国产一区二区三区| 99九九线精品视频在线观看视频| 男女那种视频在线观看| 国产乱人视频| 天美传媒精品一区二区| 天堂网av新在线| 蜜臀久久99精品久久宅男| 国产高清有码在线观看视频| 久久精品国产亚洲av天美| 欧美+日韩+精品| 国产视频一区二区在线看| 最近2019中文字幕mv第一页| 国产美女午夜福利| 欧洲精品卡2卡3卡4卡5卡区| 丝袜喷水一区| 免费av观看视频| 国内精品一区二区在线观看| 亚洲精品一卡2卡三卡4卡5卡| 国内精品美女久久久久久| 亚洲欧美精品自产自拍| 91午夜精品亚洲一区二区三区| 婷婷精品国产亚洲av在线| 欧美+亚洲+日韩+国产| 久久久久久久久大av| 亚洲欧美中文字幕日韩二区| 国产白丝娇喘喷水9色精品| 亚洲自偷自拍三级| 特大巨黑吊av在线直播| 日韩av不卡免费在线播放| 亚洲av第一区精品v没综合| 久久久a久久爽久久v久久| 此物有八面人人有两片| 美女cb高潮喷水在线观看| 国产激情偷乱视频一区二区| 色综合亚洲欧美另类图片| 午夜爱爱视频在线播放| 成人亚洲欧美一区二区av| 国产一区二区激情短视频| 免费看日本二区| 亚洲电影在线观看av| 乱人视频在线观看| 淫妇啪啪啪对白视频| 亚洲美女黄片视频| 麻豆国产av国片精品| 国产成人一区二区在线| 长腿黑丝高跟| 久久精品国产鲁丝片午夜精品| 日韩人妻高清精品专区| 卡戴珊不雅视频在线播放| 免费人成在线观看视频色| av国产免费在线观看| 久久国内精品自在自线图片| 老熟妇乱子伦视频在线观看| 成年女人永久免费观看视频| 日韩欧美国产在线观看| 欧美日韩精品成人综合77777| 精品欧美国产一区二区三| 欧美激情国产日韩精品一区| 亚洲精品色激情综合| 麻豆乱淫一区二区| 两个人的视频大全免费| 性插视频无遮挡在线免费观看| av专区在线播放| 最新中文字幕久久久久| 成年免费大片在线观看| 高清午夜精品一区二区三区 | 国产精品综合久久久久久久免费| 欧洲精品卡2卡3卡4卡5卡区| 精品久久久久久久久久免费视频| 国产精品乱码一区二三区的特点| 日日啪夜夜撸| 一边摸一边抽搐一进一小说| 在线播放无遮挡| 国产午夜精品久久久久久一区二区三区 | 在线观看午夜福利视频| 麻豆av噜噜一区二区三区| 国产激情偷乱视频一区二区| 人人妻,人人澡人人爽秒播| 美女黄网站色视频| av女优亚洲男人天堂| 久久久欧美国产精品| 欧美zozozo另类| 最近2019中文字幕mv第一页| 精品国内亚洲2022精品成人| 国产爱豆传媒在线观看| 国产一区二区激情短视频| 麻豆国产av国片精品| 日本黄色片子视频| 丝袜喷水一区| 欧美不卡视频在线免费观看| 国产精品三级大全| 男女那种视频在线观看| 久久99热这里只有精品18| 秋霞在线观看毛片| 两个人的视频大全免费| 俺也久久电影网| 内射极品少妇av片p| 国产高清视频在线观看网站| 日本在线视频免费播放| 精品人妻视频免费看| 亚洲欧美日韩高清专用| 99视频精品全部免费 在线| 国产精品女同一区二区软件| 亚洲av中文字字幕乱码综合| 久久精品影院6| 久久精品国产99精品国产亚洲性色| 国产极品精品免费视频能看的| 一区二区三区四区激情视频 | .国产精品久久| АⅤ资源中文在线天堂| 亚洲国产精品国产精品| 男女下面进入的视频免费午夜| 狂野欧美白嫩少妇大欣赏| 国产黄片美女视频| 两个人视频免费观看高清| 欧美最黄视频在线播放免费| 亚洲自偷自拍三级| 国产视频一区二区在线看| 免费大片18禁| 18+在线观看网站| 亚洲精品色激情综合| 欧美极品一区二区三区四区| 成人三级黄色视频| 欧美色欧美亚洲另类二区| 免费观看在线日韩| 18禁裸乳无遮挡免费网站照片| 日本熟妇午夜| 国产精品女同一区二区软件| 亚洲成av人片在线播放无| 国产午夜精品论理片| 高清日韩中文字幕在线| 色尼玛亚洲综合影院| 最好的美女福利视频网| 国产中年淑女户外野战色| 国产精品久久久久久久电影| 久久天躁狠狠躁夜夜2o2o| 久久久久久久久久成人| 亚洲无线在线观看| 看片在线看免费视频| 国产精品,欧美在线| 一级av片app| 老熟妇仑乱视频hdxx| 高清毛片免费观看视频网站| 国产黄片美女视频| 免费人成视频x8x8入口观看| 亚洲最大成人中文| 日本免费a在线| 少妇的逼水好多| 国产高清视频在线观看网站| 亚洲人成网站高清观看| 97超视频在线观看视频| 51国产日韩欧美| 天天一区二区日本电影三级| 国产不卡一卡二| 永久网站在线| 男人舔奶头视频| 黄色视频,在线免费观看| 国产69精品久久久久777片| av卡一久久| 日本三级黄在线观看| 国产毛片a区久久久久| www.色视频.com| 欧美成人一区二区免费高清观看| 久久久久精品国产欧美久久久| 又黄又爽又免费观看的视频| 久久精品国产自在天天线| 国产成人a∨麻豆精品| 久久精品国产亚洲av天美| 国内精品一区二区在线观看| 少妇被粗大猛烈的视频| 高清毛片免费观看视频网站| 美女被艹到高潮喷水动态| 身体一侧抽搐| 亚洲熟妇熟女久久| 成人鲁丝片一二三区免费| av天堂中文字幕网| 天堂√8在线中文| 亚洲一区高清亚洲精品| 中文资源天堂在线| 日韩一本色道免费dvd| 亚洲国产欧美人成| 麻豆成人午夜福利视频| 久久久久免费精品人妻一区二区| 日韩制服骚丝袜av| 国产黄色视频一区二区在线观看 | 久久久久久久午夜电影| 久久久色成人| 熟妇人妻久久中文字幕3abv| 色综合亚洲欧美另类图片| 一进一出抽搐动态| 特级一级黄色大片| 国产精品一区二区三区四区久久| 国产视频内射| 女同久久另类99精品国产91| 99热网站在线观看| 高清毛片免费观看视频网站| 99热精品在线国产| 18禁黄网站禁片免费观看直播| 午夜免费激情av| 亚洲性久久影院| 久久这里只有精品中国| 三级毛片av免费| 91狼人影院| 婷婷六月久久综合丁香| 亚洲欧美日韩卡通动漫| 国产大屁股一区二区在线视频| 亚洲精品在线观看二区| 久久天躁狠狠躁夜夜2o2o| 午夜视频国产福利| 精品人妻视频免费看| 一本一本综合久久| 国产成人一区二区在线| 日本精品一区二区三区蜜桃| 精品人妻熟女av久视频| 日韩精品中文字幕看吧| 久久久久久久久久黄片| 国产亚洲欧美98| 欧美三级亚洲精品| 国产黄a三级三级三级人| 国产精品美女特级片免费视频播放器| 波多野结衣巨乳人妻| 精品一区二区免费观看| 精品一区二区三区视频在线| 黄色配什么色好看| 久久人人爽人人爽人人片va| 欧美中文日本在线观看视频| 在线观看66精品国产| 久久精品影院6| 欧美成人免费av一区二区三区| 你懂的网址亚洲精品在线观看 | 久久久色成人| 成人精品一区二区免费| 一a级毛片在线观看| 成人性生交大片免费视频hd| 欧美最新免费一区二区三区| 黑人高潮一二区| 特大巨黑吊av在线直播| 国产女主播在线喷水免费视频网站 | 亚洲精品成人久久久久久| 久久国内精品自在自线图片| 欧美激情国产日韩精品一区| 精品乱码久久久久久99久播| 国产黄色视频一区二区在线观看 | 亚洲婷婷狠狠爱综合网| 久久久久久久久中文| 久久这里只有精品中国| 一级黄片播放器| .国产精品久久| 男女边吃奶边做爰视频| 91精品国产九色| 伦理电影大哥的女人| 精品久久久久久久久av| 丝袜喷水一区| 国产高清激情床上av| 国产日本99.免费观看| 国产亚洲精品久久久久久毛片| 免费观看人在逋| 啦啦啦韩国在线观看视频| av国产免费在线观看| av女优亚洲男人天堂| 久久精品国产亚洲av涩爱 | 日本a在线网址| 99精品在免费线老司机午夜| 色吧在线观看| 欧美国产日韩亚洲一区| 蜜臀久久99精品久久宅男| 久久久久九九精品影院| 中文字幕av在线有码专区| 在线免费观看的www视频| 欧美中文日本在线观看视频| 12—13女人毛片做爰片一| 亚洲五月天丁香| 麻豆一二三区av精品| 亚洲精品色激情综合| 真实男女啪啪啪动态图| 久久精品国产自在天天线| 日本撒尿小便嘘嘘汇集6| 身体一侧抽搐| 久久韩国三级中文字幕| 天堂影院成人在线观看| 蜜臀久久99精品久久宅男| 18禁裸乳无遮挡免费网站照片| 少妇高潮的动态图| 99九九线精品视频在线观看视频| 别揉我奶头 嗯啊视频| 色在线成人网| 国产真实乱freesex| 欧美日韩综合久久久久久| 丝袜美腿在线中文| 日韩欧美在线乱码| 日日撸夜夜添| 干丝袜人妻中文字幕| 欧美3d第一页| 波野结衣二区三区在线| 在线观看美女被高潮喷水网站| 黄色欧美视频在线观看| 草草在线视频免费看| 校园春色视频在线观看| 最好的美女福利视频网| 久久午夜亚洲精品久久| 少妇高潮的动态图| 国产高清有码在线观看视频| 日韩国内少妇激情av| 成人特级av手机在线观看| 久久人妻av系列| 欧美日韩在线观看h| 免费在线观看成人毛片| 嫩草影视91久久| 中文字幕精品亚洲无线码一区| av福利片在线观看| 一夜夜www| 欧美激情国产日韩精品一区| 天美传媒精品一区二区| 国产在线男女| 亚洲国产欧洲综合997久久,| 国产精品一区二区免费欧美| 男人舔女人下体高潮全视频| 亚洲成a人片在线一区二区| 老熟妇仑乱视频hdxx| 国产亚洲av嫩草精品影院| 欧美区成人在线视频| 一区二区三区免费毛片| 亚洲av五月六月丁香网| 偷拍熟女少妇极品色| 国产在线男女| 亚洲最大成人av| 人人妻人人看人人澡| 久久久久久久久大av| 亚洲第一电影网av| av免费在线看不卡| 99热这里只有精品一区| 午夜福利18| 男人狂女人下面高潮的视频| 99国产极品粉嫩在线观看| 国产淫片久久久久久久久| 精品一区二区三区视频在线观看免费| 国产精品久久视频播放| 一级黄色大片毛片| 亚洲高清免费不卡视频| 中文亚洲av片在线观看爽| 俺也久久电影网| 九九在线视频观看精品| 久久久国产成人免费| 国产精品无大码| 天堂影院成人在线观看| 淫秽高清视频在线观看| 婷婷亚洲欧美| 麻豆成人午夜福利视频| 精华霜和精华液先用哪个| 欧美国产日韩亚洲一区| 精品一区二区免费观看| 国产综合懂色| 天堂动漫精品| 精品久久久久久久久久久久久| 男人舔女人下体高潮全视频| 成人亚洲精品av一区二区| 精华霜和精华液先用哪个| 国产91av在线免费观看| 男女做爰动态图高潮gif福利片| 色av中文字幕| 男女啪啪激烈高潮av片| 99在线视频只有这里精品首页| 亚洲欧美精品自产自拍| 高清毛片免费观看视频网站| 欧美不卡视频在线免费观看| 69人妻影院| 色综合色国产| 亚洲va在线va天堂va国产| 国产精品久久久久久久电影| 成人午夜高清在线视频| 色综合色国产| 嫩草影院入口| 熟妇人妻久久中文字幕3abv| 最近中文字幕高清免费大全6| 日韩精品中文字幕看吧| 亚洲aⅴ乱码一区二区在线播放| 国产精品一区二区三区四区免费观看 | 精品欧美国产一区二区三| 国产高清视频在线播放一区| 成人性生交大片免费视频hd| 日本免费一区二区三区高清不卡| 99久国产av精品国产电影| 国产一级毛片七仙女欲春2| 1024手机看黄色片| 两个人的视频大全免费| 久久精品夜色国产| 日本五十路高清| 久久人人爽人人片av| 国产男靠女视频免费网站| 亚洲成a人片在线一区二区| 少妇人妻一区二区三区视频| 欧美中文日本在线观看视频| 黄片wwwwww| 久久久久精品国产欧美久久久| 免费电影在线观看免费观看| 精品人妻一区二区三区麻豆 | 久久九九热精品免费| 91久久精品电影网| 乱系列少妇在线播放| 午夜福利在线在线| 欧美丝袜亚洲另类| 日本与韩国留学比较| a级毛色黄片| 人人妻人人澡欧美一区二区| 国产单亲对白刺激| avwww免费| 精品日产1卡2卡| 欧美bdsm另类| 色av中文字幕| 最新中文字幕久久久久| 晚上一个人看的免费电影| 亚洲精品日韩av片在线观看| 男人狂女人下面高潮的视频| 日韩中字成人| 亚洲美女搞黄在线观看 | 日本三级黄在线观看| 91麻豆精品激情在线观看国产| 中文在线观看免费www的网站| 午夜a级毛片| 成人亚洲精品av一区二区| 看非洲黑人一级黄片| 国产精品伦人一区二区| 日韩中字成人| 又爽又黄a免费视频| 在线免费观看的www视频| 午夜精品一区二区三区免费看| 变态另类丝袜制服| 中国美白少妇内射xxxbb| 嫩草影院入口| 午夜福利在线观看免费完整高清在 | 99久久中文字幕三级久久日本| 国产色爽女视频免费观看| 麻豆国产97在线/欧美| 日韩一区二区视频免费看| 色综合站精品国产| 国产成人freesex在线 | 日本熟妇午夜| 亚洲精品影视一区二区三区av| 三级男女做爰猛烈吃奶摸视频| 亚洲精品久久国产高清桃花| 午夜福利在线观看免费完整高清在 | 亚洲18禁久久av| 在线国产一区二区在线| 午夜亚洲福利在线播放| 亚洲色图av天堂| 国模一区二区三区四区视频| 国产免费一级a男人的天堂| 51国产日韩欧美| 久久人人精品亚洲av| 别揉我奶头 嗯啊视频| 九色成人免费人妻av| 看黄色毛片网站| 日本免费a在线| 国产成人freesex在线 | 老熟妇乱子伦视频在线观看| 国模一区二区三区四区视频| 两个人的视频大全免费| 色视频www国产| 久久这里只有精品中国| 国内精品久久久久精免费| 黄色视频,在线免费观看| 免费无遮挡裸体视频| 国产精华一区二区三区| 国产三级中文精品| 蜜桃久久精品国产亚洲av| 偷拍熟女少妇极品色| 欧美一区二区精品小视频在线| 国产在视频线在精品|