亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

基于應(yīng)力傳遞系數(shù)的分析模型優(yōu)化與土壤壓實(shí)應(yīng)力預(yù)測
作者:
作者單位:

作者簡介:

通訊作者:

中圖分類號:

基金項(xiàng)目:

山西省重點(diǎn)研發(fā)計(jì)劃項(xiàng)目(201703D21102-7)和山西省農(nóng)業(yè)科學(xué)院博士基金項(xiàng)目(YBSJJ2015)


Optimization of Analytical Model and Prediction of Soil Compaction Stress Based on Stress Transmission Coefficient
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 圖/表
  • |
  • 訪問統(tǒng)計(jì)
  • |
  • 參考文獻(xiàn)
  • |
  • 相似文獻(xiàn)
  • |
  • 引證文獻(xiàn)
  • |
  • 資源附件
  • |
  • 文章評論
    摘要:

    針對目前基于有限尺度環(huán)刀的土壤應(yīng)力傳遞系數(shù)(Stress transmission coefficient,STC)取值方法無法滿足不同深度土壤條件下集中系數(shù)隨加載環(huán)境變化研究的問題,將土壤剖面分割為有限尺度的土層,基于分析模型推導(dǎo)ΠSTC公式,以多層土壤應(yīng)力傳遞系數(shù)連乘方式計(jì)算田間指定深度土壤應(yīng)力傳遞系數(shù)?;趥鞲衅骷夹g(shù)進(jìn)行田間原位土壤平板下陷試驗(yàn),通過控制壓板直徑和土層厚度實(shí)測9種加載狀態(tài)下土壤的應(yīng)力傳遞系數(shù);同時,通過有限尺度(Φ50×50mm環(huán)刀)取樣于室內(nèi),結(jié)合土壓力傳感器進(jìn)行非擾動土單軸壓縮試驗(yàn),測量各土層(0~50mm、50~100mm、100~150mm、150~200mm)應(yīng)力傳遞系數(shù)。運(yùn)用ΠSTC公式計(jì)算3種深度(100、150、200mm)土壤的應(yīng)力傳遞系數(shù)分別為0.30、0.17、0.07,綜合實(shí)測數(shù)據(jù)通過雙因素方差分析研究應(yīng)力傳遞系數(shù)隨加載環(huán)境的變化規(guī)律,由此反算不同加載條件的集中系數(shù)。結(jié)果顯示,隨著壓板尺度的改變,實(shí)測與計(jì)算所得相同深度土壤的應(yīng)力傳遞系數(shù)間并無顯著差異,表明土壤應(yīng)力傳遞系數(shù)與壓板-土壤接觸面當(dāng)量半徑無關(guān),利用ΠSTC公式計(jì)算田間土壤應(yīng)力傳遞系數(shù)方法可行;隨土層厚度的增加,應(yīng)力傳遞系數(shù)顯著減小,說明應(yīng)力傳遞性能隨土層厚度的增加而逐漸減弱;集中系數(shù)隨壓板直徑和土層厚度的增加而逐漸減小。利用分析模型較為準(zhǔn)確地預(yù)測了田間指定加載環(huán)境和土壤環(huán)境中因連續(xù)加載而變化的土壤應(yīng)力,優(yōu)化了土壤壓實(shí)應(yīng)力傳遞的研究方法。

    Abstract:

    Predicting soil stress with analytical models requires proper selection of the models’ concentration factor. The parameter is a coupled result from both loading condition and the soil environment. Stress transmission coefficient (denoted as STC) was suggested in other study to investigate the soil state’s effect on the concentration factor. Because the current limitedscale analytical approach of stress transmission coefficient may prevent accurate estimation of soil stress, there was a desperate need to make loading conditions’ impact clear on concentration factor. The function of the concentration factor was transformed and a theory to calculate the soil stress transmission coefficient insitu soil in field, ΠSTC equation, was derived, which complement, associated with the stress transmission coefficient in a limited scale after splitting the soil profile from large. Totally nine loading conditions were tested using insitu soil by controlling three plate diameters and three soil thicknesses, and a modified oedometer testing setup with a soil stress sensor was used to measure stress transmission coefficient of different soil layers (0~50mm, 50~100mm, 100~150mm and 150~200mm) indoor. Stress transmission coefficient for the same depths with field experiment was 0.30, 0.17 and 0.07, and then calculated by ΠSTC equation. Correlation analysis were performed to evaluate both measured and calculated STCs on controlled loading conditions (e.g. equivalent radius of the contact area and soil thickness). Then soil stress was predicted following the concentration factor backcalculated from the acquired STCs. The highly linear correlation between soil stress and applied surface stress indicated a stable STC for a particular soil state in field. In general, a thicker soil layer led to a decreased STC, and there was no significant difference in STCs varied with equivalent radius of the contact area, suggesting that the ΠSTC equation could be used as a specific method to quantify soil stress transmission in field. The backcalculation of concentration factor from measured STCs showed the details of how the concentration factor was affected by the changed loading condition with measured result. A good accuracy of the soil stress prediction based analytical model and ΠSTC equation meant a optimized solution was proposed for soil compacting stress prediction.

    參考文獻(xiàn)
    相似文獻(xiàn)
    引證文獻(xiàn)
引用本文

賀亭峰,丁啟朔,張偉,姜春霞,劉恩科.基于應(yīng)力傳遞系數(shù)的分析模型優(yōu)化與土壤壓實(shí)應(yīng)力預(yù)測[J].農(nóng)業(yè)機(jī)械學(xué)報(bào),2020,51(10):292-298. HE Tingfeng, DING Qishuo, ZHANG Wei, JIANG Chunxia, LIU Enke. Optimization of Analytical Model and Prediction of Soil Compaction Stress Based on Stress Transmission Coefficient[J]. Transactions of the Chinese Society for Agricultural Machinery,2020,51(10):292-298.

復(fù)制
分享
文章指標(biāo)
  • 點(diǎn)擊次數(shù):
  • 下載次數(shù):
  • HTML閱讀次數(shù):
  • 引用次數(shù):
歷史
  • 收稿日期:2020-05-21
  • 最后修改日期:
  • 錄用日期:
  • 在線發(fā)布日期: 2020-10-10
  • 出版日期: 2020-10-10