分級加載條件下深部灰?guī)r蠕應變特性研究
發(fā)布時間：2018-12-12 13:16
【摘要】：為研究深部灰?guī)r蠕應變特性,采用GDS-VIS三軸流變儀對不同深度試樣做分級加載單軸蠕變試驗�；谠囼灲Y果,計算出灰?guī)r長期強度與瞬時強度之比的均值為0.758,且深度越深比值越小;分析不同深度灰?guī)r在各分級應力水平下軸向蠕應變增量與加載級數的變化規(guī)律,并將蠕應變增量進行一次累加,得到軸向蠕應變。結果表明:蠕應變增量隨級數的增加呈現先減小后劇增的變化規(guī)律,且隨深度增加,蠕應變增量達到谷底所對應的應力百分比有明顯增大趨勢;在分級加載過程中,隨級數增加,軸向蠕應變先后呈現減速增加、等速增加和加速增加3個發(fā)展階段;當恒載應力百分比為60%~70%時,蠕應變趨于穩(wěn)定,當超過該范圍后,蠕應變加速增加直至發(fā)生蠕變破壞。研究得到的這一應力百分比范圍可以為識別深部灰?guī)r是否會發(fā)生蠕變破壞提供依據。
[Abstract]:In order to study the vermicular strain characteristics of deep limestone, uniaxial creep tests with GDS-VIS triaxial rheometer were performed on specimens with different depths. Based on the experimental results, the average value of the ratio of long-term strength to instantaneous strength of limestone is 0.758, and the ratio of depth to depth is smaller. The variation law of axial vermicular strain increment and loading series of limestone with different depth under various graded stress levels is analyzed. The creep strain increment is accumulated once and the axial vermicular strain is obtained. The results show that the increment of vermicular strain decreases at first and then increases sharply with the increase of series, and with the increase of depth, the percentage of stress corresponding to crease of vermicular strain increases obviously. In the process of step loading, with the increase of series, the axial creep strain increases successively, and increases at equal speed and accelerates at three stages of development. When the percentage of dead load stress is 60 ~ 70, the vermicular strain tends to be stable, and when it exceeds this range, the creep strain accelerates until creep failure occurs. The obtained stress percent range can provide a basis for identifying whether creep failure will occur in deep limestone.
【作者單位】： 江西理工大學資源與環(huán)境工程學院;江西理工大學江西省礦業(yè)工程重點實驗室;
【基金】：國家自然科學基金項目(51564012) 江西省科技支撐計劃項目(20141BBE50005)
【分類號】：TU45
本文編號：2374632
[Abstract]:In order to study the vermicular strain characteristics of deep limestone, uniaxial creep tests with GDS-VIS triaxial rheometer were performed on specimens with different depths. Based on the experimental results, the average value of the ratio of long-term strength to instantaneous strength of limestone is 0.758, and the ratio of depth to depth is smaller. The variation law of axial vermicular strain increment and loading series of limestone with different depth under various graded stress levels is analyzed. The creep strain increment is accumulated once and the axial vermicular strain is obtained. The results show that the increment of vermicular strain decreases at first and then increases sharply with the increase of series, and with the increase of depth, the percentage of stress corresponding to crease of vermicular strain increases obviously. In the process of step loading, with the increase of series, the axial creep strain increases successively, and increases at equal speed and accelerates at three stages of development. When the percentage of dead load stress is 60 ~ 70, the vermicular strain tends to be stable, and when it exceeds this range, the creep strain accelerates until creep failure occurs. The obtained stress percent range can provide a basis for identifying whether creep failure will occur in deep limestone.
【作者單位】： 江西理工大學資源與環(huán)境工程學院;江西理工大學江西省礦業(yè)工程重點實驗室;
【基金】：國家自然科學基金項目(51564012) 江西省科技支撐計劃項目(20141BBE50005)
【分類號】：TU45
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1 宋飛;趙法鎖;;分級加載下巖土流變的神經網絡模型[J];巖土力學;2006年07期
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