Two examples concerning pullout test of rock bolt and an anchor bolts reinforcing slope are calculated and analyzed . the ideal results have verified the validity of the method and its ability to solve the problems in engineering 上述工作完成后,應(yīng)用本文方法對錨桿的拉拔試驗(yàn)進(jìn)行了數(shù)值模擬,得到了較好的計(jì)算結(jié)果,從而證明了本文計(jì)算方法的正確性。
Through direct pullout test , we examine the effect of the water to cement ratio , contend of steel fiber and silica fume on the bond behavior ; compare the bond behavior of two types of cfrp bars with difference surface treatment ( r1 bars and g1 bars ) , and reprocess the one of inferior bond strength ; investigate the bond stress distribution along the bond length of cfrp bars , and assess the adequacy of some exist analytical models of bond - slip behavior to reproduce the experimental bond behavior 本文主要通過直接拉拔試驗(yàn),考察水膠比、鋼纖維摻量、硅灰摻量以及cfrp筋的表面處理類型等材料參數(shù)對粘結(jié)性能的影響,并對粘結(jié)效果較差的cfrp筋研究了表面處理方法,以提高cfrp筋與rpc的粘結(jié)性能;通過在cfrp筋表面粘貼應(yīng)變片,測定了粘結(jié)應(yīng)力沿cfrp筋埋長的分布情況,并對現(xiàn)有的粘結(jié)滑移本構(gòu)模型與試驗(yàn)結(jié)果的擬合效果進(jìn)行了比較。
Thirdly writer , using linear elastic theory and finite element program ( ansys ) , analyzed expanding bolt pullout test . fifthly , writer using the modified mohr - coulomb failure theory , on the base of curving failure surface , derived a theoretical formula between pullout force and compressive strength . then the thesis compared the formula with the strength - detecting formula of expanding bolt pullout method 本文采用ansys有限元程序?qū)γ浰ò纬龇ㄔ囼?yàn)過程進(jìn)行彈性理論分析;以修正的摩爾-庫侖破壞準(zhǔn)則,在擬合實(shí)際破壞面的基礎(chǔ)上推導(dǎo)出極限狀態(tài)下脹栓拔出法的混凝土拔出力與混凝土抗壓強(qiáng)度的理論公式,并把該公式與脹栓拔出法測強(qiáng)公式進(jìn)行了比較。
Based on the pull - out tests data between geogrids and expansive soil / sands arranged by the orthogonal table l9 ( 34 ) , the following conclusions are reached : 1 ) the displacement - properties of pullout tests depend on the pullout speed . the law of factors " affecting degree , which influences the parameters between geogrids and soils in the pulling - out procedure , is obtained . with the concept of " equivalent pull - out displacement ( x ) " brought forward , the whole process of pull out tests is divided into two process - " main process ( when x 1 . 0 ) " and " residual process ( when x 1 . 0 ) " , and three stages - static friction resistance stage , slip friction resistance stage , and residual friction resistance stage 基于正交設(shè)計(jì)表l9 ( 3 ~ 4 )分別安排了影響因素與土工格柵膨脹土或砂土界面相互作用參數(shù)的拉拔試驗(yàn)數(shù)據(jù),獲悉: 1 )拉拔試驗(yàn)位移特性主要取決于影響因素中拉拔速率;通過分析并獲取影響因素對筋土界面相互作用參數(shù)的影響程度及其在拉拔試驗(yàn)過程中的變化規(guī)律,提出了當(dāng)量拉拔位移( x )的概念,并據(jù)此將拉拔試驗(yàn)全過程劃分成“主過程( x 1 . 0 ) ”和“殘余過程( x 1 . 0 ) ” ;且將影響因素對拉拔力或摩擦阻力系數(shù)的影響程度分成三階段(靜摩擦阻力階段、滑動摩擦阻力階段,殘余摩擦阻力階段) ; 2 )不同(規(guī)范)定義的筋土界面摩擦阻力系數(shù)數(shù)值相差較大,但影響因素對摩擦阻力系數(shù)影響程度及其變化規(guī)律不會因不同(規(guī)范)定義而受到影響。
The friction coefficient , critical vertical loads and critical frictional resistance strength have been worked out by means of the pullout tests under the different vertical loads , analysis of frictional characteristics between soil and material and analysis of the different work mechanism between direct shear test and pullout tests . the creep characteristic parameters of some typical reinforcement materials have been obtained by the creep tests under the loads for a long time and the rheological analysis 對幾種典型筋材在不同法向荷載下進(jìn)行了拉拔試驗(yàn),并進(jìn)行了筋材與土介質(zhì)的界面摩擦特性分析,直剪試驗(yàn)與拉拔試驗(yàn)不同機(jī)理分析,找出了影響摩擦特性試驗(yàn)結(jié)果的主要因素;得出了筋材在工作荷載階段的摩擦系數(shù)、臨界法向中南大學(xué)博士學(xué)位論文荷載和臨界摩阻強(qiáng)度。