本文關(guān)鍵詞： 土壤壓實(shí) 分析模型 集中系數(shù) 土壤環(huán)境 應(yīng)力傳遞系數(shù)　出處：《農(nóng)業(yè)機(jī)械學(xué)報(bào)》2017年06期 　論文類型：期刊論文

【摘要】：機(jī)械壓實(shí)是造成土壤退化的重要原因之一,研究并預(yù)測(cè)土壤應(yīng)力有助于科學(xué)規(guī)劃田間機(jī)械使用,緩解壓實(shí)問題。基于分析模型預(yù)測(cè)土壤應(yīng)力的關(guān)鍵在于選擇合適的集中系數(shù)。然而在已有的研究中集中系數(shù)取值混亂,導(dǎo)致該模型使用時(shí)存在很大爭議,其原因在于對(duì)該參數(shù)隨土壤環(huán)境的變化缺乏規(guī)律性認(rèn)識(shí)。本文通過對(duì)集中系數(shù)表達(dá)式的進(jìn)一步推導(dǎo),在理論上提出了能夠代表土壤環(huán)境對(duì)集中系數(shù)影響的無量綱參數(shù)σ_z/σ_0,定義為應(yīng)力傳遞系數(shù)(STC)�；谒就梁忘S棕壤兩種土壤,通過控制含水率和濕密度于室內(nèi)重塑30種狀態(tài)的土壤,在單軸壓縮實(shí)驗(yàn)中運(yùn)用土壓力傳感器測(cè)量計(jì)算應(yīng)力傳遞系數(shù),建立應(yīng)力傳遞系數(shù)與土壤環(huán)境參數(shù),如含水率、干密度和先期固結(jié)壓力等之間的相關(guān)性分析。結(jié)果表明應(yīng)力傳遞系數(shù)隨土壤含水率的增大而增大,土壤初始干密度和先期固結(jié)壓力與應(yīng)力傳遞系數(shù)之間負(fù)相關(guān)性明顯。根據(jù)所得應(yīng)力傳遞系數(shù)計(jì)算相應(yīng)土壤狀態(tài)下的集中系數(shù),其取值在1.20~12.39之間,與以往的研究結(jié)果相差不大,但包含了關(guān)于集中系數(shù)隨土壤環(huán)境變化的具體信息。這意味著作為一個(gè)穩(wěn)定可測(cè)的無量綱參數(shù),應(yīng)力傳遞系數(shù)為集中系數(shù)的計(jì)算提供了一個(gè)相對(duì)科學(xué)的方法,在定量描述土壤環(huán)境對(duì)集中系數(shù)影響的同時(shí),完善了分析模型。
[Abstract]:Mechanical compaction is one of the important causes of soil degradation. The key to predicting soil stress based on the analytical model is to select the appropriate concentration coefficient. However, the confusion of the concentration coefficient in the existing research leads to great controversy in the use of the model. The reason lies in the lack of regular understanding of the variation of this parameter with soil environment. The dimensionless parameter 蟽 _ (z) / 蟽 _ (0), which can represent the effect of soil environment on concentration coefficient, is proposed theoretically, and is defined as stress transfer coefficient (STC), which is based on paddy soil and yellow brown soil. Through controlling moisture content and moisture density to reconstruct 30 kinds of soil in indoor, the stress transfer coefficient was calculated by using earth pressure sensor in uniaxial compression experiment, and the stress transfer coefficient and soil environmental parameters were established. The results show that the stress transfer coefficient increases with the increase of soil moisture content. The initial dry density of soil and the pre-consolidation pressure have negative correlation with the stress transfer coefficient, and the concentration coefficient under the corresponding soil condition is calculated according to the obtained stress transfer coefficient. Its value is between 1.20 and 12.39, which is not different from the previous research results. But it contains specific information about the variation of concentration coefficient with soil environment, which means that as a stable and measurable dimensionless parameter, stress transfer coefficient provides a relatively scientific method for the calculation of concentration coefficient. At the same time, the analytical model was improved while quantitatively describing the effect of soil environment on concentration coefficient.
【作者單位】： 南京農(nóng)業(yè)大學(xué)工學(xué)院;扎林蓋大學(xué)農(nóng)業(yè)工程系;
【基金】：國家自然科學(xué)基金項(xiàng)目(41371238)
【分類號(hào)】：S152.9
【正文快照】： 引言田間機(jī)械作業(yè)過程中,土壤-輪胎交互作用產(chǎn)生土壤應(yīng)力改變土壤狀態(tài)[1-4]造成的土壤壓實(shí)是導(dǎo)致世界范圍內(nèi)土壤出現(xiàn)退化的重要原因之一[2,5-10]。研究并預(yù)測(cè)土壤應(yīng)力可以科學(xué)規(guī)劃田間機(jī)械的使用,緩解這一問題[2,11-12]。在以往的研究中,計(jì)算土壤應(yīng)力的方法有仿真法(有限元和，

本文編號(hào)：1486634