This paper focuses on the underpinning-induced ground movement due to jet-grouting. Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages ...This paper focuses on the underpinning-induced ground movement due to jet-grouting. Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages of work execution. The aim of this paper is to determine the minimum value of such movement on the basis of the findings obtained at two similar construction sites located in the Historical Center of Moscow, considering that the maximum value is usually unpredictable. Numerical simulation of the process of soil eroding agrees well with the observational data at the current stage. It was found that the minimum value of deformations （only settlement was considered in this study） due to jetgrouting is no less than 2-3 mm. By contrast, the negative scenario of deformation due to foundation underpinning is clearly demonstrated. Also, this paper provides some general solutions for excavation supporting system as well as for underpinning design.展开更多
This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 ...This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main beam.Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning structures.Different from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive forces.Settlement observations after completion construction indicate that the building as well as the proposed design measures work well.展开更多
Foundation and retaining wall failures account for the highest case of structural failures.This is a report on a study of underpinning methods used in the construction industry in Nigeria.In view of underpinning,just ...Foundation and retaining wall failures account for the highest case of structural failures.This is a report on a study of underpinning methods used in the construction industry in Nigeria.In view of underpinning,just like most engineering decisions,there is no unique solution,the research investigated technique of remedying foundation defects and whether there are innovations as regards to the underpinning methods used in Nigeria.To achieve the desired objective structured questionnaire,oral interviews and case study of an ongoing underpinning work were carried out.Result shows that differential settlement with a mean of 2.28 is the most frequent cause of foundation failure.While the continuous strip and reinforced mat with mean of 2.7 and 2.67 respectively,are most frequently used underpinning methods in Nigerian construction industry.Also 81.3%of the respondents agree that underpinning methods adopted are suitable and effective.Professionals in Nigeria have devised unique method of underpinning.It was recommended that proper and adequate site investigation should be carried out.Heavy penalties and sanctions should be meted on those construction firms that employ quack professionals.展开更多
文摘This paper focuses on the underpinning-induced ground movement due to jet-grouting. Jet-grouting technique can cause distortions as a result of an inaccurate processing sequence and/or errors made at different stages of work execution. The aim of this paper is to determine the minimum value of such movement on the basis of the findings obtained at two similar construction sites located in the Historical Center of Moscow, considering that the maximum value is usually unpredictable. Numerical simulation of the process of soil eroding agrees well with the observational data at the current stage. It was found that the minimum value of deformations （only settlement was considered in this study） due to jetgrouting is no less than 2-3 mm. By contrast, the negative scenario of deformation due to foundation underpinning is clearly demonstrated. Also, this paper provides some general solutions for excavation supporting system as well as for underpinning design.
基金Sponsored by the Research Foundation of State Key Lab of Subtropical Building Science(Grant No.2014KB28)
文摘This paper introduces the structural design optimization of a tall building with reinforced concrete frame-core shear walls in Guangzhou downtown.To decrease the construction cost,wide flat beam with 400 mm ×650 mm rectangular cross-section are adopted for main beam.Special measures are used to decrease noncoincident centers of mass and stiffness.Because subway tunnels cross the building underground,inclined columns,the second and third floor underground together function as the underpinning structures.Different from traditional transform beam,the proposed underpinning structures show good performance without using large dimensional bending members.Special attentions should be paid to the beams connecting with the inclined column in the underpinning structures,and these beams show large tensile or compressive forces.Settlement observations after completion construction indicate that the building as well as the proposed design measures work well.
文摘Foundation and retaining wall failures account for the highest case of structural failures.This is a report on a study of underpinning methods used in the construction industry in Nigeria.In view of underpinning,just like most engineering decisions,there is no unique solution,the research investigated technique of remedying foundation defects and whether there are innovations as regards to the underpinning methods used in Nigeria.To achieve the desired objective structured questionnaire,oral interviews and case study of an ongoing underpinning work were carried out.Result shows that differential settlement with a mean of 2.28 is the most frequent cause of foundation failure.While the continuous strip and reinforced mat with mean of 2.7 and 2.67 respectively,are most frequently used underpinning methods in Nigerian construction industry.Also 81.3%of the respondents agree that underpinning methods adopted are suitable and effective.Professionals in Nigeria have devised unique method of underpinning.It was recommended that proper and adequate site investigation should be carried out.Heavy penalties and sanctions should be meted on those construction firms that employ quack professionals.
