本文關(guān)鍵詞：華南風(fēng)化花崗巖劈拉斷裂行為的試驗(yàn)與細(xì)觀模擬研究　出處：《工程力學(xué)》2017年06期 　論文類型：期刊論文

  更多相關(guān)文章： 風(fēng)化花崗巖 顆粒離散元 細(xì)觀數(shù)值模型 非均質(zhì)性 空間相關(guān)

【摘要】：為研究不同風(fēng)化程度花崗巖在劈拉受載下的破損行為,該文對(duì)廣東從化地區(qū)新鮮、微風(fēng)化、中風(fēng)化三種風(fēng)化程度的花崗巖進(jìn)行微觀特征測(cè)量及巴西圓盤試驗(yàn)研究。分別基于考慮空間相關(guān)特征的隨機(jī)模型和數(shù)字圖像技術(shù)兩種方法實(shí)現(xiàn)對(duì)巖樣細(xì)觀結(jié)構(gòu)的表征,結(jié)合細(xì)觀參數(shù)反演技術(shù),建立反映巖石細(xì)觀非均質(zhì)組構(gòu)特性的顆粒離散元模型,對(duì)花崗巖劈拉試驗(yàn)進(jìn)行數(shù)值仿真試驗(yàn)研究。結(jié)果表明,隨著風(fēng)化級(jí)別的提高,花崗巖中粘結(jié)力較強(qiáng)的長石等礦物向粘土礦物轉(zhuǎn)化,結(jié)晶強(qiáng)度降低,微孔隙等軟弱結(jié)構(gòu)增多,巖石宏觀力學(xué)性能不斷劣化,劈拉破壞由單一裂紋主導(dǎo)轉(zhuǎn)為多條分叉狀裂紋,巖樣脆性也逐漸減弱。基于兩種方法建立的細(xì)觀隨機(jī)力學(xué)模型仿真結(jié)果均表明巖樣的劈拉強(qiáng)度隨風(fēng)化級(jí)別的提高逐漸降低,與試驗(yàn)結(jié)果變化趨勢(shì)相符,分析得到不同風(fēng)化花崗巖的劈拉破裂響應(yīng)特征與試驗(yàn)結(jié)果一致,且從細(xì)觀層面對(duì)花崗巖樣受劈拉作用的漸進(jìn)破裂響應(yīng)提供了深入認(rèn)識(shí)。
[Abstract]:In order to study the breakage behavior of granite with different weathering degree under splitting load, this paper is fresh and breezy in Conghua area, Guangdong Province. Three kinds of weathered granites with medium weathering degree were measured by microcosmic characteristics and studied by Brazilian disk test. Based on the stochastic model with spatial correlation and digital image technology, the mesoscopic structure of rock samples was realized. Sign. Combined with the technique of mesoscopic parameter inversion, a discrete element model of particles reflecting the characteristics of meso-heterogeneous fabric of rock is established, and the numerical simulation experiment of granite splitting tensile test is carried out. The results show that with the increase of weathering level. The feldspar and other minerals with strong adhesion in granite are transformed into clay minerals, the crystallization strength decreases, the weak structures such as micropores increase, and the macroscopic mechanical properties of the rocks continue to deteriorate. Cleavage failure is changed from single crack to multiple branched crack. The simulation results of mesoscopic stochastic mechanics model based on the two methods show that the splitting tensile strength of rock samples decreases with the increase of weathering level, which is consistent with the change trend of test results. The characteristics of cleavage fracture response of different weathered granites are consistent with the experimental results, and a deep understanding of the progressive fracture response of granitic samples subjected to split tension is provided from the meso level.
【作者單位】： 華南理工大學(xué)土木與交通學(xué)院;清華大學(xué)水利水電工程系;華南理工大學(xué)亞熱帶建筑科學(xué)國家重點(diǎn)實(shí)驗(yàn)室;
【基金】：國家自然科學(xué)基金項(xiàng)目(51109083) 中央高�；究蒲袠I(yè)務(wù)費(fèi)項(xiàng)目(2014ZZ0009) 國家自然科學(xué)基金委員會(huì)-中國鐵路總公司高速鐵路基礎(chǔ)研究聯(lián)合基金項(xiàng)目(U1434211) 中電建華東勘測(cè)設(shè)計(jì)院有限公司2013年科技項(xiàng)目(SD2013-10)
【分類號(hào)】：TU452
【正文快照】： 華南地區(qū)花崗巖長時(shí)間受外界自然條件影響,尤其是強(qiáng)烈地風(fēng)化作用,導(dǎo)致其礦物成分、結(jié)構(gòu)狀態(tài)、物理力學(xué)性質(zhì)等均產(chǎn)生一定改變。特別是廣東地區(qū),氣候更加溫暖濕潤,工程地質(zhì)性質(zhì)特殊,花崗巖受化學(xué)風(fēng)化作用更強(qiáng)烈,風(fēng)化程度差異較大,使得該地區(qū)環(huán)境災(zāi)害、工程地質(zhì)災(zāi)害經(jīng)常發(fā)生。作，

本文編號(hào)：1403323