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International Concrete Abstracts Portal

Showing 1-5 of 10 Abstracts search results

Document: 

SP83-08

Date: 

October 1, 1994

Author(s):

David W. Moller, Henry L. Minch, and Joseph P. Welsh

Publication:

Symposium Papers

Volume:

83

Abstract:

The Helms Pumped Storage Project is a new hydroelectric facility located in the Sierra Nevada mountains O f California. During excavation of the underground powerhouse complex, a previously unidentified shear zone was encountered in the granitic rock. The shear zone was a near vertical plane, up to 35 ft. in stratigraphic thickness, and was intersected by several tunnels near the powerhouse. During initial water filling of the power tunnel, the shear zone became a conduit for high pressure tunnel water (818 psi), allowing it to leave the power tunnel and seep into adjoining dry access tunnels. An innovative grouting program utilizing ultrafine cement (Blaine fineness of 8,880 cm /g) and pump pressures which were increased progressively with depth (up to 700 psi) was used to create a barrier between the pressure tunnel and the shear zone. The grouting program successfully reduced ground water pressures and seepage downstream of the barrier to acceptable levels. The program demonstrated the superior penetrating capability of grout made with ultrafine cement compared to type II and type III portland cement, and indicates that ultrafine cement grout can be an effective substitute for chemical grout when the properties of a cement grout are required.

DOI:

10.14359/6341


Document: 

SP83-04

Date: 

October 1, 1984

Author(s):

Charles V. Logie

Publication:

Symposium Papers

Volume:

83

Abstract:

Results from load testing of one-meter-diameter drilled concrete piers showed that the majority of the piers designed as foundation support for the 37-story Jakarta Mandarin Hotel failed to meet load test criteria. The potential causes for load test failure and the load deflection characteristics of the piers were investigated. A layer of unconsolidated sediment of varying thickness was encountered between the pier tips and the bearing strata. Extensive coring through the pier shafts was undertaken to develop data to statistically characterize the thickness and spatial distribution of the unconsolidated sedi-ments. A rehabilitation technique was developed which con-sisted of flushing the sediments from the pier tips utilizing high pressure water jets followed by subsequent cement grouting of the resulting voids. The technique was developed so that production rehabilitation could be practically and reliably achieved. The rehabilitation mechanism filled the void space created in the unconsolidated sediments with grout. The grout intruded and compacted the coarser sediments which remained in the voids. Load testing of the rehabilitated piers showed compli-ance with load testing criteria.

DOI:

10.14359/6337


Document: 

SP83-06

Date: 

October 1, 1984

Author(s):

John G. Ruggiero

Publication:

Symposium Papers

Volume:

83

Abstract:

Tail void filling of soft ground shield driven tunnels has historically been conducted through the use of pea gravel and neat cement grout. This method has normally resulted in some settlement, infiltration of grout into utilities and divided the Engineer and Contractor on the question of how close to the tunnel heading grouting should be conducted. On the recently completed Red Hook Interceptor Sewer, a soft ground shield driven compressed air tunnel in New York City, a contract modification was made to use a low slump, 5-7 inches (12-18 cm), low shrink grout mixture of cement, limeflour, benton-ite and admixtures in lieu of pea gravel and neat cement grout. Placement was made at two to five times overburden pressures in close proximity to subsurface utilities and into the tail of the shield. Settlement monitoring indicated negligible settlement along the tunnel route. This paper describes the use and advantages of this method.

DOI:

10.14359/6339


Document: 

SP83

Date: 

October 1, 1984

Author(s):

Editor: Joseph P. Welsh / Sponsored by: ACI Committee 552

Publication:

Symposium Papers

Volume:

83

Abstract:

A study and report on the application and use of cement grouting techniques. Includes chapters on: the use of condensed silica fume in grouts; design and grouting of a concrete lined high pressure tunnel; changes in length and volume of cementitious grouts; drilled pier foundation rehabilitation; acoustic emissions as a nondestructive testing method; low slump compactive tail shield grouting in soft ground; bentonite effect on pumpability of compaction grouts; ultrafine cement pressure grouting; and cold weather cement grouting and post tensioning. Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP83

DOI:

10.14359/14040


Document: 

SP83-03

Date: 

October 1, 1984

Author(s):

Della M. Roy, M. Perez, B.E. Scheetz, and P.H. Licastro

Publication:

Symposium Papers

Volume:

83

Abstract:

Changes in length and volume of cementitious grouts for use in nuclear waste isolation have been investigated, and com-pared with the behavior of other mixtures, neat cement pastes, fly-ash containing mixtures, and mixtures with high-range water reducers (‘superplasticizers’). Expansive and non-expansive for-mulations are compared with respect to their changes in length and volume, both at atmospheric pressure and elevated curing condi-t ions, including those simulating placement under pressures of up to 1600 psi hydrostatic.

DOI:

10.14359/6336


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