This document discusses groundwater control techniques for tunnelling and shaft sinking projects. It describes techniques for controlling groundwater by pumping arrays of wells or by using physical exclusion methods like cut-off walls. Selecting the appropriate technique depends on factors like soil permeability and the required depth of groundwater lowering. The document also outlines some challenges for tunnelling like controlling running sand conditions and constructing cross-passages between tunnels.
This is about types of shear failure in soil, describe all the three types of the bearing capacity failure of soil.
This is prepared by (Abdullah Kawkas Galaly) a student in civil engineering department at Salahaddin University in Erbil-Kurdistan region.
This is about types of shear failure in soil, describe all the three types of the bearing capacity failure of soil.
This is prepared by (Abdullah Kawkas Galaly) a student in civil engineering department at Salahaddin University in Erbil-Kurdistan region.
Tunnel is an artificially constructed underground passage to by- pass obstacles safely without disturbing the over burden. This module explains about tunnels, their parts, types and importance.
INTRODUCTION TO DRAG LINE AND THEIR WORKING PROCESS PLUS THEIR TYPE AND USES IN CONSTRUCTION SITE
THIS PRESENTATION IS OVER THE CONSTRUCTION EQUIPMENT USED IN DAILY BASIS
Tunnel is an artificially constructed underground passage to by- pass obstacles safely without disturbing the over burden. This module explains about tunnels, their parts, types and importance.
INTRODUCTION TO DRAG LINE AND THEIR WORKING PROCESS PLUS THEIR TYPE AND USES IN CONSTRUCTION SITE
THIS PRESENTATION IS OVER THE CONSTRUCTION EQUIPMENT USED IN DAILY BASIS
Dewatering is a term to describe the removal of groundwater or surface water from for example a construction site. In construction the water is pumped from wells or sumps to temporarily lower the groundwater levels, to allow excavation in dry and stable conditions below natural groundwater level.
Presentation by Er Vivek Kapadia, FIE showing the application of Geo Synthetics in canals done at Workshop on GeoTextiles in Civil engineering organized by #IEIGSC
Stormwater management for challenging sites. This slide show was used for a class presented on Dec 5, 2013 at the Rogue Valley Sewer Services in Central Point, OR.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
2. www.preene.com
GROUNDWATER CONTROL TECHNIQUES
Synopsis
• Background and definitions
• Groundwater control techniques:
– by pumping
– by exclusion
• Guidelines for selecting the best technique
• Some tunnelling and shaft sinking problems
• A bit of dewatering design and philosophy
3. www.preene.com
PRACTICE PROFILE
Preene Groundwater Consulting is the Professional Practice
of Dr Martin Preene and provides specialist advice and design
services in the fields of dewatering, groundwater engineering
and hydrogeology to clients worldwide
Dr Martin Preene has more than 25 years’ experience on
projects worldwide in the investigation, design, installation
and operation of groundwater control and dewatering
systems. He is widely published on dewatering and
groundwater control and is the author of the UK industry
guidance on dewatering (CIRIA Report C515 Groundwater
Control Design and Practice) as well as a dewatering text book
(Groundwater Lowering in Construction: A Practical Guide to
Dewatering)
4. www.preene.com
GROUNDWATER CONTROL
Definition
Groundwater Control
“The process of temporarily dealing with groundwater, to allow
excavations to be made in dry and stable conditions below natural
groundwater level”
May be known as Dewatering or Construction Dewatering or
Groundwater Lowering
5. www.preene.com
GROUNDWATER CONTROL
Additional Definitions:
Permeability = coefficient of permeability = hydraulic conductivity
(units of m/s). Typically given the symbol k
High to moderate permeability:
Gravel, sand and gravel, sand, silty sand
Porous and fractured rock
Low to very low permeability:
Silt, clay
Unfissured and ‘tight’ rock
Drawdown = amount of vertical lowering of groundwater level due to
pumping (units of metres)
6. www.preene.com
GROUNDWATER CONTROL
Two main philosophies of groundwater control:
• Pumping: Arrays of wells or sumps (construction
dewatering)
• Exclusion: Physical cut-off walls
7. www.preene.com
GROUNDWATER CONTROL BY PUMPING
• Typically relies on
arrays or groups of
pumped wells and/or
sumps, acting
together, to lower
groundwater levels
over a wide area
• Commonly known as
dewatering
15. www.preene.com
• Shaft or caisson
constructed
• Perforated ‘laterals’
driven out from
shaft
• One pump (located
in the shaft) can
achieve high yields,
can be much more
widely spaced than
conventional
deepwells
COLLECTOR WELLS
20. www.preene.com
EXCLUSION: VERTICAL CUT-OFF AND HORIZONTAL BARRIERS
Cut-off walls do not reach deep
impermeable stratum:
horizontal barrier is used to exclude
groundwater from base
21. www.preene.com
JOINTS AND LEAKS IN CUT-OFF WALLS
Walls installed as panels or sections
Walls installed
as line of
overlapping
columns
Walls or barriers installed
as multiple line of
overlapping columns
26. www.preene.com
CONCRETE DIAPHRAGM WALLS
Rope operated
diaphragm wall grab
Construction sequence for diaphragm walls
from Woodward (2005): An Introduction to
Geotechnical Processes
Source: Bachy Soletanche
Rockmill diaphragm
wall cutter (hydromill
or Hydrofraise)
Source: Cementation Skanska
27. www.preene.com
BORED PILE WALLS
Contiguous pile wall – concrete piles installed at a spacing of more than one pile diameter
Secant pile wall – overlapping concrete piles installed at a spacing of less than one pile diameter
29. www.preene.com
BENTONITE SLURRY WALLS
Bentonite-cement slurry wall
constructed by long reach
excavator
Common European practice
Soil-bentonite slurry wall
constructed by long reach
excavator
Common North American
practice
30. www.preene.com
GROUTING
Definition:
• Grouting is the process of controlled injection of a
fluid (grout) into the pores (in soil) or fissures (in
rock) of the ground, where the grout sets and
changes the properties of the in-situ material,
typically by reducing permeability and increasing
strength
31. www.preene.com
GROUTING IN SOILS AND ROCKS
Permeation grouting
(in soils) – little or no
disturbance of
soil structure
Rock
grouting –
little or no
disturbance of
rock structure
32. www.preene.com
GROUTING
• Most grouts are suspensions of particles in water (with
other additives). Cement-based grouts are the most
common type used for groundwater control
• The penetration distance of grout into soil and rock is
controlled by the relative sizes of the grout particles
and the soil or rock openings. Distance of penetration
is often very limited, unless the soil is very porous or
the rock fissures are very open
35. www.preene.com
JET GROUTING
Jet grouting rig operating with jetting
head above ground level
Source: Keller Geotechnique
Jet grouting systems from
Woodward (2005): An
Introduction to
Geotechnical Processes
38. www.preene.com
ARTIFICIAL GROUND FREEZING (BRINE)
AGF using brine circulation Portable brine freeze plant – This freeze plant is driven by a
180-kW electric motor. The output is 166 320 kcal/h when
evaporating at −37.5°C
Source: British Drilling and Freezing Co. Ltd
39. www.preene.com
ARTIFICIAL GROUND FREEZING (LN)
Schematic diagram of
liquid nitrogen (LN) freezing
system
On-site liquid nitrogen (LN) storage tank
receiving a LN delivery by road tanker
40. www.preene.com
RANGE OF APPLICATION OF METHODS
Amount of
lowering of
groundwater
level
Low permeability (silts) High permeability (gravels)
From CIRIA Report
C515 (2000):
Groundwater
Control: Design
and Practice
41. www.preene.com
RANGE OF APPLICATION OF METHODS
Low permeability (silts) High permeability (gravels)
From CIRIA Report
C515 (2000):
Groundwater
Control: Design
and Practice
42. www.preene.com
SOME TUNNELLING AND SHAFT SINKING PROBLEMS
There are some interesting problems and challenges associated
with tunnelling and shaft sinking projects:
• The tunnel as a drain
• Running sand
• Tunnelling without ‘dewatering’
• Advance dewatering of tunnels
• Cross-passage construction
43. www.preene.com
THE TUNNEL AS A DRAIN
• A tunnel being constructed
with an open face will act as a
drain and water will enter the
tunnel
• If rates of groundwater inflow
are manageable, and face
instability is not a concern (e.g.
in rock) then this can be a
viable method of ‘groundwater
control’
• Inflows can be reduced by
grouting ahead of the tunnel
44. www.preene.com
THE TUNNEL AS A DRAIN
• Geometry of the groundwater flow regime can be more
complex in long section
Example of segmentally lined tunnel with open face shield
Direction of progress
Groundwater flow
Groundwater level lowered
above working face
45. www.preene.com
RUNNING SAND
• Running sand is often mentioned
in relation to ‘bad ground’ in
tunnelling and shaft sinking
• It is not a type of material, it is a
state in which a granular material
can exist, when pore water
pressures are high and the
material strength becomes very
low
• Dewatering can lower pore water
pressures and transform material
into more stable ground
Running sand in the base of a shaft
46. www.preene.com
RUNNING SAND
s‘ = s - u
Soil shear strength
t = s’tanf’
Effective stress = total stress - pore water pressure
Groundwater
flow
Sump pumping
within an
underpinned shaft
47. www.preene.com
RUNNING SAND
Dewatering used to lower groundwater levels and
prevent running sand during shaft construction in
Glacial Sand deposits
Groundwater
flow
Underpinned shaft
with advance
dewatering by
external wells
48. www.preene.com
TUNNELLING WITHOUT DEWATERING
• On many projects shafts or vertical structures may be
dewatered, but the tunnel itself is not dewatered
directly, even where it is below groundwater level
• Tunnelling can still be carried out in a ‘shirt sleeve
environment’
• This is the result of a groundwater exclusion
approach
• This can be achieved by compressed air working or
full face TBMs (EPB or slurry)
50. www.preene.com
COMPRESSED AIR WORKING
• Compressed air working for tunnelling was developed in the
late 19th century
• Up until the 1980s and 1990s compressed air was used
relatively widely in the UK to allow hand or mechanised
excavation below groundwater level using open face shields
• There are health risks associated with compressed air working
(decompression sickness, bone necrosis)
• Compressed air working is now largely limited to short term
use such as interventions to access the front of a TBM to
change cutters mid-drive or to deal with obstructions
52. www.preene.com
ADVANCE DEWATERING OF TUNNELS
• While shafts and tunnel portals are routinely dewatered, it is rare to
carry out advance dewatering for tunnel drives themselves
• This may be due to lack of surface access for wells, or because
tunnelling methods (e.g. TBMs) do not require it
• However, even if dewatering of tunnel drives is not ‘necessary’
there can be operational and efficiency advantages from
dewatering (or depressurisation) of tunnel drives:
– Improved production rates
– Reduced moisture content of spoil
– Easier (depressurised) conditions for cross-passage construction and
TBM cutter head maintenance
53. www.preene.com
ADVANCE DEWATERING OF TUNNELS
• On the Jubilee Line Extension (JLE) project in London
in the late 1990s a de-facto advance dewatering
system in the Chalk and Basal Sands was adopted
when the drawdown effect of dewatered
neighbouring shafts interacted
• This allowed the existing TBMs to operate in open
mode (rather than closed mode), thereby improving
tunnel production
54. www.preene.com
ADVANCE DEWATERING OF TUNNELS
• The Channel Tunnel Rail Link (CTRL) London Running Tunnels took this
a stage further in the early 2000s and developed a planned advance
dewatering system to depressurise the Chalk and Basal Sands.
• 39 wells at 22 locations, pumping up to 700 l/s
• This highlighted some of the challenges of advance dewatering:
– The Project Client had to purchase parcels of land on which to locate the
wells
– The local sewer network could not cope with the pumped dewatering flow
rate, so a 3.5 km long water disposal main (up to 600 mm diameter) had to
be constructed below the streets
• Some of the wells were installed to water industry standards and were
subsequently adopted by Thames Water
55. www.preene.com
CROSS-PASSAGE CONSTRUCTION
• Many transportation tunnels are twin bore, and
require cross-passages to be constructed periodically
along the route for access, maintenance and
ventilation
• Other headings or tunnel enlargements may be
needed at shafts and stations
• If the tunnels are constructed by full-face TBMs, then
the cross-passages may be the only explicit
groundwater control required for the tunnels
56. www.preene.com
CROSS-PASSAGE CONSTRUCTION
• The geometry can be difficult, short drives between
tunnels, often in poorly investigated areas
• Groundwater exclusion strategies can be attractive –
grouting, artificial ground freezing
• Groundwater depressurisation – radial wells – can also
be used. The wells will flow naturally into the tunnel, but
usually need to be pumped
• Challenges relate to drilling out through tunnel lining for
wells, including sub-horizontally and upwards