This study focuses on the analytical prediction of subsurface settlement induced by shield tunnelling in sandy cobble stratum considering the volumetric deformation modes of the soil above the tunnel crown.A series of...This study focuses on the analytical prediction of subsurface settlement induced by shield tunnelling in sandy cobble stratum considering the volumetric deformation modes of the soil above the tunnel crown.A series of numerical analyses is performed to examine the effects of cover depth ratio(C/D),tunnel volume loss rate(h t)and volumetric block proportion(VBP)on the characteristics of subsurface settle-ment trough and soil volume loss.Considering the ground loss variation with depth,three modes are deduced from the volumetric deformation responses of the soil above the tunnel crown.Then,analytical solutions to predict subsurface settlement for each mode are presented using stochastic medium theory.The influences of C/D,h t and VBP on the key parameters(i.e.B and N)in the analytical expressions are discussed to determine the fitting formulae of B and N.Finally,the proposed analytical solutions are validated by the comparisons with the results of model test and numerical simulation.Results show that the fitting formulae provide a convenient and reliable way to evaluate the key parameters.Besides,the analytical solutions are reasonable and available in predicting the subsurface settlement induced by shield tunnelling in sandy cobble stratum.展开更多
In reviewing the scientific explorations in human settlements in the past century, as well as the new accomplishments in the study on Chinese human settlements, the author proposes that the Sciences of Human Settlemen...In reviewing the scientific explorations in human settlements in the past century, as well as the new accomplishments in the study on Chinese human settlements, the author proposes that the Sciences of Human Settlements should respond to a series of new situations and chal-lenges of world development, such as global climate change and development mode transformation, in order to embody the ideal of "a Greater Science, a Greater Humanism, and a Greater Art". It is argued that the development tendencies of Sciences of Human Settlements in China should include: the concern for people's livelihood based on the principle of people-oriented, the enhancement of strategic spatial planning for the new modes of spatial growth, the rising of ecological awareness for the Green Revolution, the balance of urban and rural development for rational urbanization, the exploration for the Third System from the perspectives of both Eastern and Western cultures, the innovations on the education of human settlements and the creation of both a better environment and a harmonious society.展开更多
The primary theoretical framework of the Sciences of Human Settlements was established based on the researches and practices for decades. Nowadays, it is facing a new start in order to face the challenges of "tra...The primary theoretical framework of the Sciences of Human Settlements was established based on the researches and practices for decades. Nowadays, it is facing a new start in order to face the challenges of "transformation" and "restructuring" amid the process of urbanization. It means that, in both the theoretical and practical fields of the Sciences of Human Settlements, due attention should be paid to the discussions on urbanization strategies, the rethinking on balanced urban-rural development, the extension and integration of various disciplines, and the realization of experimental projects in various localities. The Sciences of Human Settlements should be more closely connected with related sciences and technologies and learn more from the traditional "Chinese wisdom," so as to establish the system of "Grand Science, Grand Humanism and Grand Arts." The practice of the Sciences of Human Settlements should highlight the integration of both strategies and methodologies, the completion of institutions, and the monitoring at the macro-level. Both the top-down strategic planning and design and the bottom-up comprehensive community construction are necessary. Now that the times of great transition brings us an opportunity to solve problems creatively, the Sciences of Human Settlements should be further researched and explored.展开更多
基金This study was supported by the National Natural Science Foundation of China(Grant Nos.51538001 and 51978019).
文摘This study focuses on the analytical prediction of subsurface settlement induced by shield tunnelling in sandy cobble stratum considering the volumetric deformation modes of the soil above the tunnel crown.A series of numerical analyses is performed to examine the effects of cover depth ratio(C/D),tunnel volume loss rate(h t)and volumetric block proportion(VBP)on the characteristics of subsurface settle-ment trough and soil volume loss.Considering the ground loss variation with depth,three modes are deduced from the volumetric deformation responses of the soil above the tunnel crown.Then,analytical solutions to predict subsurface settlement for each mode are presented using stochastic medium theory.The influences of C/D,h t and VBP on the key parameters(i.e.B and N)in the analytical expressions are discussed to determine the fitting formulae of B and N.Finally,the proposed analytical solutions are validated by the comparisons with the results of model test and numerical simulation.Results show that the fitting formulae provide a convenient and reliable way to evaluate the key parameters.Besides,the analytical solutions are reasonable and available in predicting the subsurface settlement induced by shield tunnelling in sandy cobble stratum.
文摘In reviewing the scientific explorations in human settlements in the past century, as well as the new accomplishments in the study on Chinese human settlements, the author proposes that the Sciences of Human Settlements should respond to a series of new situations and chal-lenges of world development, such as global climate change and development mode transformation, in order to embody the ideal of "a Greater Science, a Greater Humanism, and a Greater Art". It is argued that the development tendencies of Sciences of Human Settlements in China should include: the concern for people's livelihood based on the principle of people-oriented, the enhancement of strategic spatial planning for the new modes of spatial growth, the rising of ecological awareness for the Green Revolution, the balance of urban and rural development for rational urbanization, the exploration for the Third System from the perspectives of both Eastern and Western cultures, the innovations on the education of human settlements and the creation of both a better environment and a harmonious society.
文摘The primary theoretical framework of the Sciences of Human Settlements was established based on the researches and practices for decades. Nowadays, it is facing a new start in order to face the challenges of "transformation" and "restructuring" amid the process of urbanization. It means that, in both the theoretical and practical fields of the Sciences of Human Settlements, due attention should be paid to the discussions on urbanization strategies, the rethinking on balanced urban-rural development, the extension and integration of various disciplines, and the realization of experimental projects in various localities. The Sciences of Human Settlements should be more closely connected with related sciences and technologies and learn more from the traditional "Chinese wisdom," so as to establish the system of "Grand Science, Grand Humanism and Grand Arts." The practice of the Sciences of Human Settlements should highlight the integration of both strategies and methodologies, the completion of institutions, and the monitoring at the macro-level. Both the top-down strategic planning and design and the bottom-up comprehensive community construction are necessary. Now that the times of great transition brings us an opportunity to solve problems creatively, the Sciences of Human Settlements should be further researched and explored.
