發(fā)布時(shí)間：2018-01-11 16:27

  本文關(guān)鍵詞：全長(zhǎng)錨固系統(tǒng)失效機(jī)制及耐久性探究　出處：《中國礦業(yè)大學(xué)》2017年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 全長(zhǎng)錨固 拉拔試驗(yàn) 預(yù)應(yīng)力支護(hù) 失效機(jī)制 聲發(fā)射

【摘要】：為揭示全長(zhǎng)錨固系統(tǒng)的失效機(jī)制,本文基于理論分析、實(shí)驗(yàn)室測(cè)試、現(xiàn)場(chǎng)實(shí)踐探討了決定全長(zhǎng)錨固系統(tǒng)耐久性的主要因素。研究涉及了錨固對(duì)象承載力修復(fù)細(xì)觀機(jī)理、錨固界面的漸進(jìn)損傷過程以及巖層離層下的損傷過程、全長(zhǎng)預(yù)應(yīng)力錨固的可靠性測(cè)試及實(shí)施、分段鋼管錨固下的錨固失效機(jī)制、以及循環(huán)載荷下錨固系統(tǒng)耐久性評(píng)價(jià),最后對(duì)全長(zhǎng)錨固系統(tǒng)的發(fā)展方向做以簡(jiǎn)要展望,主要結(jié)論如下:(1)提出了一種新型注漿樹脂材料來實(shí)現(xiàn)全長(zhǎng)錨固,并采用這種材料對(duì)常見煤系地層的煤樣和砂巖試樣進(jìn)行了峰后強(qiáng)度修復(fù)測(cè)試。測(cè)試表明該注漿樹脂在加固碎裂煤巖體方面有一定優(yōu)越性,同時(shí)提出了實(shí)現(xiàn)全長(zhǎng)錨固的具體流程。對(duì)全長(zhǎng)錨固系統(tǒng)錨固劑-圍巖黏結(jié)界面的失效機(jī)制進(jìn)行了分析研究,提出了漸進(jìn)式的失效特征,對(duì)不同黏結(jié)狀態(tài)下的界面剪力和軸力分布形式展開了理論分析,從界面黏結(jié)狀態(tài)改變的角度上探討了錨固力驟降機(jī)制。(2)研究表明層狀頂板離層條件下錨固界面保持其彈性狀態(tài)時(shí)對(duì)應(yīng)一個(gè)臨界離層寬度。未超過離層寬度時(shí),界面剪應(yīng)力分布對(duì)離層位于錨固系統(tǒng)中的具體位置不敏感,錨固系統(tǒng)也相對(duì)穩(wěn)定;超過該寬度后,離層兩側(cè)界面的黏結(jié)狀態(tài)將發(fā)生改變且對(duì)離層位置變動(dòng)較為敏感。當(dāng)離層位于錨固系統(tǒng)端頭位置附近時(shí),錨固系統(tǒng)受到的影響最大,而位于尾部時(shí),受到的影響最小。實(shí)驗(yàn)室測(cè)試驗(yàn)證了離層兩側(cè)界面剪力分布的合理性。(3)研究提出一種新型水泥基錨固袋來實(shí)現(xiàn)預(yù)應(yīng)力全長(zhǎng)錨固。實(shí)驗(yàn)室拉拔測(cè)試表明預(yù)拉力全長(zhǎng)錨固系統(tǒng)相較于傳統(tǒng)端錨更穩(wěn)定,承載力更強(qiáng)。聲發(fā)射測(cè)試表明預(yù)拉力的升高帶來損傷事件總數(shù)的降低,且事件分布逐漸向桿體自身和錨固端頭方向遷移,高預(yù)拉力條件下決定全長(zhǎng)錨固系統(tǒng)承載性能的為桿體抗拉強(qiáng)度。研究成果在青海能源大通煤礦得到成功應(yīng)用,圍巖變形控制效果顯著。(4)為模擬不同厚度互層巖體下錨固系統(tǒng)失效特性,研究了由不同分段鋼管通過端面黏結(jié)形成的組合鋼管在錨固拉拔作用下的分離機(jī)制。研究認(rèn)為錨固系統(tǒng)的失效形式、拉拔力波動(dòng)特點(diǎn)、拉拔力和拉拔位移大小都和鋼管夾持端的分段鋼管長(zhǎng)度有緊密關(guān)聯(lián),研究同時(shí)提出了鋼管內(nèi)應(yīng)力分布的理論模型。(5)探討了不同直徑錨桿錨固系統(tǒng)在循環(huán)載荷下的動(dòng)力響應(yīng)特性。實(shí)驗(yàn)證實(shí)了錨固鋼管內(nèi)合理的應(yīng)力分布形式,特定循環(huán)模式下錨固系統(tǒng)也具有“變形記憶”特性和流變特性,但是較難觀察到類似于巖石在循環(huán)動(dòng)載下所表現(xiàn)出的“塑性滯回環(huán)”特征。錨固系統(tǒng)的失效形式與錨固方式、循環(huán)動(dòng)載特性都有很大關(guān)系。
[Abstract]:In order to reveal the failure mechanism of full-length anchoring system, this paper is based on theoretical analysis and laboratory testing. The main factors that determine the durability of the full-length anchoring system are discussed in the field practice. The research involves the meso-mechanism of the bearing capacity of the anchoring object, the progressive damage process of the Anchorage interface and the damage process under the rock layer. The reliability test and implementation of full-length prestressed Anchorage, the failure mechanism of Anchorage in segmented steel tubes, and the durability evaluation of Anchorage system under cyclic load are also discussed. Finally, the development direction of Full-length Anchorage system is briefly prospected. The main conclusions are as follows: (1) A new grouting resin material is proposed to achieve full-length anchoring. The post-peak strength of coal samples and sandstone samples in common coal measure strata were tested by this kind of material. The test results show that the grouting resin has some advantages in strengthening fractured coal and rock mass. At the same time, the concrete flow of full-length anchoring is put forward. The failure mechanism of anchor-surrounding rock bond interface of full-length anchoring system is analyzed and studied, and the progressive failure characteristics are put forward. The distribution of interfacial shear force and axial force in different bonding states is analyzed theoretically. The mechanism of sudden drop of anchoring force is discussed from the point of view of the change of interfacial bonding state. The results show that when the Anchorage interface keeps its elastic state under the condition of layered roof separation, it corresponds to a critical layer width, which does not exceed the layer separation width. The interfacial shear stress distribution is not sensitive to the specific position of the separated layer in the Anchorage system, and the Anchorage system is relatively stable. When the width exceeds, the bonding state of the interface between the two sides of the separation layer will change and be sensitive to the change of the location of the separation layer. When the layer is located near the end of the Anchorage system, the Anchorage system will be most affected. And at the end. The effect is minimal. Laboratory tests verify the rationality of shear distribution at the interface between the two sides of the separation layer. A new cement-based anchoring bag is proposed to realize the full-length prestressed anchoring. The laboratory pull test shows that the full-length pre-tension anchoring system is more stable than the traditional end-anchor system. The acoustic emission test shows that the increase of pretension force leads to the decrease of the total number of damage events, and the distribution of the events gradually moves to the direction of the rod itself and the anchoring end. Under the condition of high pretension, the bearing capacity of the full-length anchoring system is determined by the tensile strength of the rod body. The research results have been successfully applied in Qinghai energy source Datong coal mine. The deformation control effect of surrounding rock is significant. 4) the failure characteristics of anchoring system under interbedded rock mass with different thickness are simulated. The separation mechanism of composite steel pipe formed by different sections of steel pipe through end bonding under the action of anchoring and drawing is studied. The failure form of the anchoring system and the characteristics of pull-out force fluctuation are considered. Drawing force and drawing displacement are closely related to the length of steel pipe at the clamping end. At the same time, a theoretical model of stress distribution in steel pipe is proposed.) the dynamic response characteristics of anchoring system with different diameters under cyclic load are discussed, and the reasonable stress distribution in anchored steel pipe is verified by experiments. Anchorage system also has the characteristics of "deformation memory" and rheology under specific cyclic mode. However, it is difficult to observe the characteristics of "plastic hysteresis loop" similar to that of rock under cyclic dynamic load. The failure form of anchoring system is closely related to anchoring mode and cyclic dynamic load characteristic.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：TD353.6
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本文編號(hào)：1410316