螺旋錨錨周土體變形試驗(yàn)與抗拔承載力計(jì)算模型研究
發(fā)布時(shí)間：2018-07-31 05:00
【摘要】：螺旋錨作為一種廣泛應(yīng)用于房屋建筑、擋土結(jié)構(gòu)、輸電線塔、交通運(yùn)輸?shù)阮I(lǐng)域的抗拔錨固基礎(chǔ)具有施工速度快、環(huán)境破壞小、節(jié)約建設(shè)成本等特點(diǎn)。但由于錨-土相互作用的復(fù)雜性,目前對(duì)其抗拔機(jī)理和性能的理論研究遠(yuǎn)不能滿足工程需要。已有研究主要通過(guò)假定破壞面提出了各種計(jì)算理論,由于受傳統(tǒng)測(cè)試手段限制無(wú)法獲取螺旋錨上拔過(guò)程中錨周土體破壞面的精準(zhǔn)形狀,從而導(dǎo)致很多理論成果在分析錨周土體變形機(jī)理時(shí)出現(xiàn)了較大的誤差,目前螺旋錨的設(shè)計(jì)主要依賴于工程經(jīng)驗(yàn)。鑒于傳統(tǒng)試驗(yàn)方法的局限性,本文采用非接觸式數(shù)字圖像相關(guān)模型試驗(yàn)方法,對(duì)螺旋單錨和群錨的上拔過(guò)程開(kāi)展模型試驗(yàn)研究,深入探討了錨周土體的變形機(jī)理：通過(guò)對(duì)大量變形場(chǎng)試驗(yàn)數(shù)據(jù)的對(duì)比分析,確定了影響單錨抗拔承載力的控制因素,建立了更為符合工程實(shí)際情況的螺旋錨多參數(shù)抗拔承載力預(yù)測(cè)模型；通過(guò)對(duì)群錨模型變形場(chǎng)的研究,提出了不同組合形式下的群錨效應(yīng)理論及抗拔承載力計(jì)算方法,主要工作如下：(1)針對(duì)螺旋錨錨周土體變形研究的復(fù)雜性,將數(shù)字圖像測(cè)量技術(shù)用于錨周土體變形測(cè)量,設(shè)計(jì)了相關(guān)試驗(yàn)裝置,實(shí)現(xiàn)了力加載系統(tǒng)與基于DIC技術(shù)的StrainMaster圖像采集系統(tǒng)的有效結(jié)合。通過(guò)對(duì)同等試驗(yàn)條件下實(shí)測(cè)位移與StrainMaster系統(tǒng)得到的位移場(chǎng)進(jìn)行對(duì)比分析,結(jié)果表明StrainMaster系統(tǒng)得到的測(cè)試結(jié)果具有較高的精度,能夠?qū)崿F(xiàn)錨周土體變形過(guò)程測(cè)量的可視化,從而為實(shí)現(xiàn)錨周土體的精確測(cè)量提供了技術(shù)支持。該方法具有操作簡(jiǎn)單、實(shí)時(shí)測(cè)量、無(wú)干擾、精度高等優(yōu)點(diǎn)。(2)螺旋單錨上拔過(guò)程中錨周土體變化是一個(gè)復(fù)雜的動(dòng)態(tài)過(guò)程,受很多因素影響,并表現(xiàn)為不同的抗拔力學(xué)性能。為了分析其抗拔承載力的控制因素,揭示錨周土體的變形破壞機(jī)理,分別對(duì)不同密實(shí)度和不同埋深砂土中螺旋單錨進(jìn)行了試驗(yàn)研究,系統(tǒng)分析了錨周土體的位移變形規(guī)律,得到了不同上拔力階段下螺旋單錨錨周土體的變形特征。(3)通過(guò)對(duì)螺旋單錨錨周土體變形場(chǎng)的研究,系統(tǒng)分析了螺旋單錨抗拔破壞的力學(xué)機(jī)理,基于剪脹理論確定了破壞面形狀,提出了單錨臨界埋深率和砂土相對(duì)密實(shí)度之問(wèn)的關(guān)系,根據(jù)極限平衡理論構(gòu)建了能反映淺埋和深埋破壞機(jī)理的螺旋單錨抗拔承載力計(jì)算模型,并與其他學(xué)者的試驗(yàn)研究結(jié)果進(jìn)行了對(duì)比分析。結(jié)果表明,該計(jì)算模型的預(yù)測(cè)結(jié)果與試驗(yàn)結(jié)果具有較好的一致性,可實(shí)現(xiàn)不同密實(shí)度砂土中螺旋單錨抗拔承載力的合理預(yù)測(cè)。(4)通過(guò)對(duì)不同密實(shí)度砂土中螺旋群錨試驗(yàn)研究,分析了錨周土體變形破壞機(jī)理和群錨上拔過(guò)程中上拔力-位移關(guān)系曲線特征。試驗(yàn)結(jié)果表明,群錨抗拔承載力具有明顯的疊加效應(yīng),且砂土密實(shí)度、埋深和錨間距等參數(shù)對(duì)群錨效應(yīng)具有顯著影響。在此基礎(chǔ)上,根據(jù)試驗(yàn)成果建立了群錨效應(yīng)系數(shù)與砂土密實(shí)度、群錨間距以及埋深率之間的量化關(guān)系,為群錨效應(yīng)計(jì)算提供了理論依據(jù)。(5)在群錨效應(yīng)理論分析的基礎(chǔ)上,建立了不同組合形式下螺旋群錨效應(yīng)系數(shù)的計(jì)算模型。通過(guò)對(duì)不同工況下群錨效應(yīng)系數(shù)的計(jì)算,并與現(xiàn)有試驗(yàn)研究結(jié)果的對(duì)比分析,該計(jì)算模型能夠?qū)θ哄^效應(yīng)的試驗(yàn)結(jié)果進(jìn)行較好的預(yù)測(cè),從而解決了群錨抗拔承載力的計(jì)算問(wèn)題。
[Abstract]:Spiral anchor, widely used in buildings, retaining structure, transmission line tower, transportation and other fields, has the characteristics of fast construction speed, small environmental damage and saving construction cost. However, because of the complexity of the interaction of anchor soil, the theoretical research on its pulling mechanism and performance can not meet the needs of the project at present. The existing research mainly puts forward various calculation theories by assuming the failure surface. Due to the limitation of the traditional testing method, the precise shape of the failure surface of the anchor soil in the uplift process can not be obtained. So a lot of theoretical results have a large error in the analysis of the deformation mechanism of the anchorage soil, and the design of the spiral anchor is mainly based on the design. In view of the limitations of the project, in view of the limitations of the traditional test method, this paper uses a non-contact digital image correlation model test method to carry out a model test study on the spiral single anchor and the uplift process of the group anchor, and deeply discusses the deformation mechanism of the anchor soil. By comparing and analyzing the data of a large number of deformation field tests, the single anchor is determined. The prediction model of multi parameter anti pullout bearing capacity of spiral anchor which is more in line with the actual situation of the project is established. Through the study of the deformation field of the group anchor model, the theory of group anchor effect under different combination forms and the calculation method of uplift bearing capacity are proposed. The main work is as follows: (1) the soil change of the spiral anchor anchors is changed. The digital image measurement technology is applied to the measurement of soil deformation in the anchor soil, and the related experimental device is designed. The effective combination of the force loading system with the StrainMaster image acquisition system based on DIC technology is realized. The displacement field obtained by the measured displacement and the StrainMaster system under the same test conditions is compared and analyzed. The results show that the test results obtained by the StrainMaster system have high accuracy and can realize the visualization of the measurement of the deformation process of the soil anchor soil, thus providing technical support for the accurate measurement of the anchor soil. The method has the advantages of simple operation, real time measurement, no interference and high precision. (2) the anchor cycle in the uplift process of spiral single anchor. Soil change is a complex dynamic process, which is influenced by many factors and shows different pullout mechanical properties. In order to analyze the controlling factors of its uplift bearing capacity, the deformation and failure mechanism of the surrounding soil is revealed, and the spiral single anchors in different compactness and different buried depth sand soil are tested and studied. The anchor soil is systematically analyzed. The deformation characteristics of the displacement and deformation of the body are obtained. (3) through the study of the deformation field of the soil of the spiral single anchor, the mechanical mechanism of the uplift failure of the spiral single anchor is systematically analyzed. Based on the theory of dilatancy, the shape of the failure surface is determined, and the critical depth of the single anchor and the relative density of the sand soil are put forward. The calculation model of the uplift bearing capacity of spiral single anchor which can reflect the mechanism of shallow and deep burial failure is constructed according to the theory of limit equilibrium, and the results are compared with the experimental results of other scholars. The results show that the prediction results of the model are in good agreement with the experimental results, and can realize different compactness. The reasonable prediction of the uplift bearing capacity of the spiral single anchor in the sandy soil. (4) through the study of the spiral group anchors in the sand soil with different density, the deformation and failure mechanism of the soil anchored soil and the relation curve of the uplift displacement relation in the uplift process of the anchors are analyzed. The experimental results show that the uplift bearing capacity of the group anchor has obvious superposition effect and the sand is dense. The parameters such as degree, buried depth and anchor spacing have significant influence on the group anchor effect. On this basis, according to the experimental results, the quantitative relation between the group anchor effect coefficient and the sand density, the spacing of the group anchor and the depth of the buried depth is established. (5) on the basis of the theory analysis of the group anchor effect, the different groups are established. The calculation model of the effect coefficient of the spiral group anchorage under the combined form. Through the calculation of the group anchor effect coefficient under different working conditions and comparing with the existing experimental results, this model can predict the experimental results of the group anchor effect better, thus solving the calculation problem of the anti pullout carrying capacity of the group anchor.
【學(xué)位授予單位】：鄭州大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU476
，
本文編號(hào)：2154475
[Abstract]:Spiral anchor, widely used in buildings, retaining structure, transmission line tower, transportation and other fields, has the characteristics of fast construction speed, small environmental damage and saving construction cost. However, because of the complexity of the interaction of anchor soil, the theoretical research on its pulling mechanism and performance can not meet the needs of the project at present. The existing research mainly puts forward various calculation theories by assuming the failure surface. Due to the limitation of the traditional testing method, the precise shape of the failure surface of the anchor soil in the uplift process can not be obtained. So a lot of theoretical results have a large error in the analysis of the deformation mechanism of the anchorage soil, and the design of the spiral anchor is mainly based on the design. In view of the limitations of the project, in view of the limitations of the traditional test method, this paper uses a non-contact digital image correlation model test method to carry out a model test study on the spiral single anchor and the uplift process of the group anchor, and deeply discusses the deformation mechanism of the anchor soil. By comparing and analyzing the data of a large number of deformation field tests, the single anchor is determined. The prediction model of multi parameter anti pullout bearing capacity of spiral anchor which is more in line with the actual situation of the project is established. Through the study of the deformation field of the group anchor model, the theory of group anchor effect under different combination forms and the calculation method of uplift bearing capacity are proposed. The main work is as follows: (1) the soil change of the spiral anchor anchors is changed. The digital image measurement technology is applied to the measurement of soil deformation in the anchor soil, and the related experimental device is designed. The effective combination of the force loading system with the StrainMaster image acquisition system based on DIC technology is realized. The displacement field obtained by the measured displacement and the StrainMaster system under the same test conditions is compared and analyzed. The results show that the test results obtained by the StrainMaster system have high accuracy and can realize the visualization of the measurement of the deformation process of the soil anchor soil, thus providing technical support for the accurate measurement of the anchor soil. The method has the advantages of simple operation, real time measurement, no interference and high precision. (2) the anchor cycle in the uplift process of spiral single anchor. Soil change is a complex dynamic process, which is influenced by many factors and shows different pullout mechanical properties. In order to analyze the controlling factors of its uplift bearing capacity, the deformation and failure mechanism of the surrounding soil is revealed, and the spiral single anchors in different compactness and different buried depth sand soil are tested and studied. The anchor soil is systematically analyzed. The deformation characteristics of the displacement and deformation of the body are obtained. (3) through the study of the deformation field of the soil of the spiral single anchor, the mechanical mechanism of the uplift failure of the spiral single anchor is systematically analyzed. Based on the theory of dilatancy, the shape of the failure surface is determined, and the critical depth of the single anchor and the relative density of the sand soil are put forward. The calculation model of the uplift bearing capacity of spiral single anchor which can reflect the mechanism of shallow and deep burial failure is constructed according to the theory of limit equilibrium, and the results are compared with the experimental results of other scholars. The results show that the prediction results of the model are in good agreement with the experimental results, and can realize different compactness. The reasonable prediction of the uplift bearing capacity of the spiral single anchor in the sandy soil. (4) through the study of the spiral group anchors in the sand soil with different density, the deformation and failure mechanism of the soil anchored soil and the relation curve of the uplift displacement relation in the uplift process of the anchors are analyzed. The experimental results show that the uplift bearing capacity of the group anchor has obvious superposition effect and the sand is dense. The parameters such as degree, buried depth and anchor spacing have significant influence on the group anchor effect. On this basis, according to the experimental results, the quantitative relation between the group anchor effect coefficient and the sand density, the spacing of the group anchor and the depth of the buried depth is established. (5) on the basis of the theory analysis of the group anchor effect, the different groups are established. The calculation model of the effect coefficient of the spiral group anchorage under the combined form. Through the calculation of the group anchor effect coefficient under different working conditions and comparing with the existing experimental results, this model can predict the experimental results of the group anchor effect better, thus solving the calculation problem of the anti pullout carrying capacity of the group anchor.
【學(xué)位授予單位】：鄭州大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU476
，
本文編號(hào)：2154475
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