scholarly journals Research and development support of the spacer system for the foundation pit constructed by the Moscow method

2021 ◽  
Vol 31 (4) ◽  
pp. 51-65
Author(s):  
M. I. Farfel ◽  
M. I. Gukova ◽  
D. V. Kondrashov ◽  
D. Yu. Konyashin
Keyword(s):  
Research And Development ◽  
Mechanical Strain ◽  
Strain Gauges ◽  
Foundation Pit ◽  
Construction Technique ◽  
Metal Structures ◽  
Emergency Situations ◽  
Floor Slabs ◽  
Development Support ◽  
Soil Excavation

The article presents the results obtained during the research and development support for the construction of the foundation pit for a projected hotel near the Kursky railway station in Moscow using the truss spacer system fixed in the diaphragm wall. This construction technique, called the “Moscow method” ensures the gradual soil excavation between the pit walls along tiers reinforced by steel spacer trusses to be performed simultaneously with installation of floor slabs. The developed and approved at TsNIISK named after V.A. Kucherenko method for determining stresses (deformations) in elements of metal structures using mechanical strain gauges with a removable indicator was applied to monitor the construction of a unique structure. During the monitoring, emergency situations, requiring extra measures for eliminating the identified unacceptable stresses in the structures, were identified. The provided example demonstrates the research and development support to a prerequisite for the construction of unique buildings and structures.

Monitoring and Analysis for the Deformation of SMW Retaining Structures in Subway Station

2014 ◽  
Vol 580-583 ◽  
pp. 1249-1253
Author(s):  
Jiang Tao Xia ◽  
Shao Fei Zhang ◽  
Hua Rong Shen ◽  
Ze Jun Liu ◽  
Shi Qing Huang
Keyword(s):  
Early Stage ◽  
Horizontal Displacement ◽  
Ground Subsidence ◽  
Subway Station ◽  
Deep Soil ◽  
Foundation Pit ◽  
Retaining Structures ◽  
Soil Mixing ◽  
Wall Structures ◽  
Soil Excavation

The monitoring is carried out for deformation of the soil-mixing-wall structures used in Baijihu subway station. The horizontal displacement of deep soil is obtained, as well as the ground subsidence around the edges of the foundation pit. Their variation rules under the influence of some factors, such as soil excavation and support settings etc, is analyzed. The results show that during the process of SMW construction, it is necessary to monitor the horizontal displacement of deep soil and the ground subsidence around the edges of the foundation pit, especially during the early stage of excavation.

Construction Technique of Cement-Soil Mixing Anchor in Foundation Pit in Soft Soil Area

2011 ◽  
Vol 261-263 ◽  
pp. 1784-1788
Author(s):  
Gan Bin Liu ◽  
Rong Hua Ye ◽  
Li Xu ◽  
Xue Yi Shen
Keyword(s):  
Soft Soil ◽  
Drill Pipe ◽  
Soft Clay ◽  
Mechanical Equipment ◽  
Pullout Capacity ◽  
Foundation Pit ◽  
Construction Technique ◽  
Soil Mixing ◽  
Design Engineers ◽  
Cement Soil

In this paper, the construction technique of a new soil anchor-the cement-soil mixing anchor, which is applicable in the area of soft clay, is introduced. During the construction of the anchor, the drill pipe and blade is served as a reinforced body and formed an anchorage body with the cement-soil body. The material and making, technics parameters, mechanical equipment and construction requirement of the cement-soil mixing anchor are presented firstly. Then, the uplift tests of the cement-soil mixing anchor are carried out, and the ultimate pullout force which is 1.6 times greater than that of the soil nailing in the same condition is obtained. At last, an application of the cement-soil mixing anchor in a foundation pit is given. The test results shown that the application of the cement-soil mixing anchor can reach the expected reinforcement effect. Therefore, this framework can then be used by design engineers to more confidently estimate the pullout capacity of cement-soil mixing anchors under tension loading.

Application of High Pressure Jet Grouting Pile with Undrained Open Caisson Combined Construction Technology in the Protection of Yangtze River Levee

2013 ◽  
Vol 368-370 ◽  
pp. 1443-1449
Author(s):  
Jun Yang Wei ◽  
Bao Tian Wang ◽  
Jing Hua Zhang ◽  
Bin Zhou
Keyword(s):  
High Pressure ◽  
Yangtze River ◽  
Engineering Application ◽  
Construction Technology ◽  
Deep Foundation ◽  
Effective Protection ◽  
Foundation Pit ◽  
Construction Technique ◽  
Deep Foundation Pit ◽  
Jet Grouting

It is easy to cause Yangtze River embankment soil slip or even collapse to have a deep foundation pit construction adjacent to Yangtze River outside embankment，with lots of risk . A new combined construction technique for large caisson is presented. The construction technology, the earthwork excavation of deep high pressure jet grouting pile combined with undrained open caisson construction technology, with data monitoring for the open caisson excavation control is adopted. This study mainly summarizes the advantages of deep high pressure jet grouting pile combined with undrained caisson combined construction technology engineering application, and describes the process of the combined construction and measures of deviation correction.The new combining construction technique has made a relatively effective protection for the Yangtze River levee and its ecological environment,having great engineering application value to some similar engineering.

scholarly journals Cost-Effective High-Performance Concrete: Experimental Analysis on Shrinkage

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2730
Author(s):  
Barbara Kucharczyková ◽  
Dalibor Kocáb ◽  
Petr Daněk ◽  
Ivailo Terzijski
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Setting Time ◽  
Mechanical Strain ◽  
Cost Effective ◽  
Strain Gauges ◽  
Early Age ◽  
Dry Air ◽  
First Case

This paper focuses on the experimental determination of the shrinkage process in Self-Compacting High-Performance Concrete (SCC HPC) exposed to dry air and autogenous conditions. Special molds with dimensions of 100 mm × 60 mm × 1000 mm and 50 mm × 50 mm × 300 mm equipped with one movable head are used for the measurement. The main aim of this study is to compare the shrinkage curves of SCC HPC, which were obtained by using different measurement devices and for specimens of different sizes. In addition, two different times t0 are considered for the data evaluation to investigate the influence of this factor on the absolute value of shrinkage. In the first case, t0 is the time of the start of measurement, in the second case, t0 is the setting time. The early-shrinkage (48 h) is continuously measured using inductive sensors leant against the movable head and with strain gauges embedded inside the test specimen. To monitor the long term shrinkage, the specimens are equipped with special markers, embedded into the specimens’ upper surface or ends. These markers serve as measurement bases for the measurement using mechanical strain gauges. The test specimens are demolded after 48 h and the long term shrinkage is monitored using the embedded strain gauges (inside the specimens) and mechanical strain gauges that are placed, in regular intervals, onto the markers embedded into the specimens’ surface or ends. The results show that both types of measurement equipment give a similar result in the case of early age measurement, especially for the specimens cured under autogenous conditions. However, the early age and especially long term measurement are influenced by the position of the measurement sensors, particularly in the case of specimens cured under dry air conditions. It was proven that the time t0 have a fundamental influence on the final values of the shrinkage of investigated SCC HPC and have a significant impact on the conclusions on the size effect.

scholarly journals Metal and Polymeric Strain Gauges for Si-Based, Monolithically Fabricated Organs-on-Chips

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 536 ◽  
Author(s):  
William F. Quirós-Solano ◽  
Nikolas Gaio ◽  
Cinzia Silvestri ◽  
Gregory Pandraud ◽  
Ronald Dekker ◽  
...  
Keyword(s):  
Mechanical Strain ◽  
Polymeric Materials ◽  
In Situ Monitoring ◽  
Strain Gauges ◽  
Heart Cells ◽  
Custom Made ◽  
And Performance ◽  
On Chip ◽  
Set Up

Organ-on-chip (OOC) is becoming the alternative tool to conventional in vitro screening. Heart-on-chip devices including microstructures for mechanical and electrical stimulation have been demonstrated to be advantageous to study structural organization and maturation of heart cells. This paper presents the development of metal and polymeric strain gauges for in situ monitoring of mechanical strain in the Cytostretch platform for heart-on-chip application. Specifically, the optimization of the fabrication process of metal titanium (Ti) strain gauges and the investigation on an alternative material to improve the robustness and performance of the devices are presented. The transduction behavior and functionality of the devices are successfully proven using a custom-made set-up. The devices showed resistance changes for the pressure range (0–3 kPa) used to stretch the membranes on which heart cells can be cultured. Relative resistance changes of approximately 0.008% and 1.2% for titanium and polymeric strain gauges are respectively reported for membrane deformations up to 5%. The results demonstrate that both conventional IC metals and polymeric materials can be implemented for sensing mechanical strain using robust microfabricated organ-on-chip devices.

Research and Development Support for the Navy Technology Center for Safety and Survivability

2001 ◽  
Author(s):  
Alexander Maranghides ◽  
S. G. Pande ◽  
J. M. Hughes ◽  
C. J. Nowack ◽  
J. T. Leonard
Keyword(s):  
Research And Development ◽  
Technology Center ◽  
Development Support
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