Influenced by traditional methods in the landscape architecture,the studies in landscape architecture science of China are fundamentally subjective and qualitative,and aim at aesthetic elements.The quantitative method...Influenced by traditional methods in the landscape architecture,the studies in landscape architecture science of China are fundamentally subjective and qualitative,and aim at aesthetic elements.The quantitative methods are commonly used in the physicism domain,and there is a great potential for the application of quantitative methods to landscape architecture science.The paper summarized the progress in the application of quantitative methods to landscape architecture science in China,in which the evaluation of eco-effect,sightseeing effect,result of disposing,economic benefit,engineering quality,greenbelts landscape,landscape patterns and usage of greenbelts,etc.were involved.It proves that quantitative methods have aroused general concern and have been well applied in certain fields and there are still some shortcomings in the researches to be improved.Finally,the important directions of Chinese landscape architecture science are proposed.展开更多
Four key stress thresholds exist in the compression process of rocks,i.e.,crack closure stress(σ_(cc)),crack initiation stress(σ_(ci)),crack damage stress(σ_(cd))and compressive strength(σ_(c)).The quantitative id...Four key stress thresholds exist in the compression process of rocks,i.e.,crack closure stress(σ_(cc)),crack initiation stress(σ_(ci)),crack damage stress(σ_(cd))and compressive strength(σ_(c)).The quantitative identifications of the first three stress thresholds are of great significance for characterizing the microcrack growth and damage evolution of rocks under compression.In this paper,a new method based on damage constitutive model is proposed to quantitatively measure the stress thresholds of rocks.Firstly,two different damage constitutive models were constructed based on acoustic emission(AE)counts and Weibull distribution function considering the compaction stages of the rock and the bearing capacity of the damage element.Then,the accumulative AE counts method(ACLM),AE count rate method(CRM)and constitutive model method(CMM)were introduced to determine the stress thresholds of rocks.Finally,the stress thresholds of 9 different rocks were identified by ACLM,CRM,and CMM.The results show that the theoretical stress−strain curves obtained from the two damage constitutive models are in good agreement with that of the experimental data,and the differences between the two damage constitutive models mainly come from the evolutionary differences of the damage variables.The results of the stress thresholds identified by the CMM are in good agreement with those identified by the AE methods,i.e.,ACLM and CRM.Therefore,the proposed CMM can be used to determine the stress thresholds of rocks.展开更多
基金Supported by the Science and Technology Project of Henan Provincial Science and Technology Department(0424490012)Major Program of Henan Institute of Science and Technology(040132)
文摘Influenced by traditional methods in the landscape architecture,the studies in landscape architecture science of China are fundamentally subjective and qualitative,and aim at aesthetic elements.The quantitative methods are commonly used in the physicism domain,and there is a great potential for the application of quantitative methods to landscape architecture science.The paper summarized the progress in the application of quantitative methods to landscape architecture science in China,in which the evaluation of eco-effect,sightseeing effect,result of disposing,economic benefit,engineering quality,greenbelts landscape,landscape patterns and usage of greenbelts,etc.were involved.It proves that quantitative methods have aroused general concern and have been well applied in certain fields and there are still some shortcomings in the researches to be improved.Finally,the important directions of Chinese landscape architecture science are proposed.
基金Projects(2021RC3007,2020RC3090)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProjects(52374150,52174099)supported by the National Natural Science Foundation of China。
文摘Four key stress thresholds exist in the compression process of rocks,i.e.,crack closure stress(σ_(cc)),crack initiation stress(σ_(ci)),crack damage stress(σ_(cd))and compressive strength(σ_(c)).The quantitative identifications of the first three stress thresholds are of great significance for characterizing the microcrack growth and damage evolution of rocks under compression.In this paper,a new method based on damage constitutive model is proposed to quantitatively measure the stress thresholds of rocks.Firstly,two different damage constitutive models were constructed based on acoustic emission(AE)counts and Weibull distribution function considering the compaction stages of the rock and the bearing capacity of the damage element.Then,the accumulative AE counts method(ACLM),AE count rate method(CRM)and constitutive model method(CMM)were introduced to determine the stress thresholds of rocks.Finally,the stress thresholds of 9 different rocks were identified by ACLM,CRM,and CMM.The results show that the theoretical stress−strain curves obtained from the two damage constitutive models are in good agreement with that of the experimental data,and the differences between the two damage constitutive models mainly come from the evolutionary differences of the damage variables.The results of the stress thresholds identified by the CMM are in good agreement with those identified by the AE methods,i.e.,ACLM and CRM.Therefore,the proposed CMM can be used to determine the stress thresholds of rocks.
