WWW.THESIS.XLIBX.INFO
FREE ELECTRONIC LIBRARY - Thesis, documentation, books
 
<< HOME
CONTACTS



Pages:     | 1 |   ...   | 10 | 11 || 13 |

«Leaders Guide Trenching and Shoring Safety - Competent Person The manual for Excavations Trenching and Shoring is produced in Adobe Acrobat. The ...»

-- [ Page 12 ] --
EXCAVATIONS LESS THAN 20 FEET DEEP(3) STABLE ROCK VERTICAL (90 Deg)

–  –  –

NOTES:

1. Numbers shown in parentheses next to maximum allowable slopes are angles expressed in degrees from the horizontal. Angles have been rounded off.

2. A short-term maximum allowable slope of 1/2H:1V (63 degrees) is allowed in excavations in Type A soil that are 12 feed (3.67 m) or less in depth. Short-term maximum allowable slopes for excavations greater than 12 feet (3.67 m) in depth shall be 3/4H:1V (53 degrees).

3. Sloping or benching for excavations greater than 20 feet deep shall be designed by a registered professional engineer.

–  –  –

Simple Slope-General Exception: Simple slope excavations which are open 24 hours or less (short term) and which are 12 feet or less in depth shall have a maximum allowable slope of 1/2:1.

Simple Slope- Short Term

2.All benched excavations 20 feet or less in depth shall have a maximum

allowable slope of 3/4 to 1 and maximum bench dimensions as follows:

Simple Bench Multiple Bench

3. All excavations 8 feet or less in depth which have unsupported vertically sided lower portions shall have a maximum vertical side 3 1/2 feet.

Unsupported Vertically Sided Lower Portion-Maximum 8 Feet Depth All excavations more than 8 feet but not more than 12 feet in depth with unsupported vertically sided lower portions shall have a maximum allowable slope of 1:1 and a maximum vertical side of 3 1/2 feet.

Unsupported Vertically Sided Lower Portion-Maximum 12 Feet in Depth All excavations 20 feet or less in depth which have vertically sided lower portions that are supported or shielded shall have a maximum allowable slope of 3/4:1.

The support or shield system must extend at least 18 inches above the top of the vertical side Supported or Shielded Vertically Sided Lower Portion B- 1.2 Excavations Made in Type B Soil

1. All simple slope excavations 20 feet or less in depth shall have a maximum allowable slope of 1:1.

Simple Slope

2. All benched excavations 20 feet or less in depth shall have a maximum

allowable slope of 1:1 and maximum bench dimensions as follows:

Single Bench Multiple Bench

3. All excavations 20 feet or less in depth which have vertically sided lower portions shall be shielded or supported to a height at least 18 inches above the top of the vertical side. All such excavations shall have a maximum allowable

slope of 1:1

Vertically Sided Lower Portion B- 1.3 Excavations Made in Type C Soil

1. All simple slope excavations 20 feet or less in depth shall have a maximum

allowable slope of 1 1/2:1

Simple Slope

2.All excavations 20 feet or less in depth which have vertically sided lower portions shall be shielded or supported to a height at least 18 inches above the top of the vertical side. All such excavations shall have a maximum allowable slope of 1 1/2:1.

Vertically Sided Lower Portion

3. All other sloped excavations shall be in accordance with the other options permitted in 1541.1(b) B- 1.4 Excavations Made in Layered Soil

1. All excavations 20 feet or less in depth made in layered soils shall have a

maximum allowable slope for each layer as set forth below:

B OVER A

C OVER A

C OVER B

A OVER B

A OVER C

B OVER C

2. All other sloped excavations shall be in accordance with the other options permitted in 1541.1(b).

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.

Appendix C Timber Shoring for Trenches §1541.1. Requirements for Protective Systems, Appendix C Timber Shoring for Trenches (a) Scope. This appendix contains information that can be used when timber shoring is provided as a method of protection from cave-ins in trenches that do not exceed 20 feet in depth. This appendix must be used when design of timber shoring protective systems is to be performed in accordance with Section 1541.1(c)(1). Other timber shoring configurations; other systems of support such as hydraulic and pneumatic systems; and other protective systems such as sloping, benching, shielding, and freezing systems must be designed in accordance with the requirements set forth in Section 1541.1(b) and 1541.1(c).

(b) Soil Classification. In order to use the data presented in this appendix, the soil type or types in which the excavation is made must first be determined using the soil classification method set forth in Article 6.

(c) Presentation of Information.

Information is presented in several forms as follows:

(1) Information is presented in tabular form in Tables C-1.1, C-1.2 and C-1.3, and Tables C-2.1, C-2.2 and C-2.3 following Section (g) of Appendix C. Each table presents the minimum sizes of timber members to use in a shoring system, and each table contains data only for the particular soil type in which the excavation or portion of the excavation is made. The data are arranged to allow the user the flexibility to select from among several acceptable configurations of members based on varying the horizontal spacing of the crossbraces. Stable rock is exempt from shoring requirements and therefore, no data are presented for this condition.





(2) Information concerning the basis of the tabular data and the limitations of the data is presented in Section (d) of this appendix, and on the tables themselves.

(3) Information explaining the use of the tabular data is presented in Section (e) of this appendix.

(4) Information illustrating the use of the tabular data is presented in Section (f) of this appendix.

(5) Miscellaneous notations regarding Tables C-1.1 through C-1.3 and Tables C-2.1 through C-2.3 are presented in Section (g) of this appendix.

(d) Basis and limitations of the data.

(1) Dimensions of timber members.

(A) The sizes of the timber members listed in Tables C-1.1 through C-1.3 are taken from the National Bureau of Standards (NBS) report, ``Recommended Technical Provisions for Construction Practice in Shoring and Sloping of Trenches and Excavations.'' In addition, where NBS did not recommend specific sizes of members, member sizes are based on an analysis of the sizes required for use by existing codes and on empirical practice.

(B) The required dimensions of the members listed in Tables C-1.1 through C-1.3 refer to actual dimensions and not nominal dimensions of the timber. Employers wanting to use nominal size shoring are directed to Tables C-2.1 through C-2.3, or have this choice under Section 1541.1(c)(3).

(2) Limitation of application.

(A) It is not intended that the timber shoring specification apply to every situation that may be experienced in the field. These data were developed to apply to the situations that are most commonly experienced in current trenching practice. Shoring systems for use in situations that are not covered by the data in this appendix must be designed as specified in Section 1541.1(c).

(B) When any of the following conditions are present, the members specified in the tables are not considered adequate. Either an alternate timber shoring system must be designed or another type of protective system designed in accordance with Section 1541.1.

1. When loads imposed by structures or by stored material adjacent to the trench weigh in excess of the load imposed by a two-foot soil surcharge. The term ``adjacent'' as used here means the area within a horizontal distance from the edge of the trench equal to the depth of the trench.

2. When vertical loads imposed on crossbraces exceed a 240-pound gravity load distributed on a one-foot section of the center of the crossbrace.

3. When surcharge loads are present from equipment weighing in excess of 20,000 pounds.

4. When only the lower portion of a trench is shored and the remaining portion of the trench is sloped or benched unless: The sloped portion is sloped at an angle less steep than three horizontal to one vertical; or the members are selected from the tables for use at a depth which is determined from the top of the overall trench, and not from the toe of the sloped portion.

(e) Use of Tables. The members of the shoring system that are to be selected using this information are the crossbraces, the uprights, and the wales, where wales are required.

Minimum sizes of members are specified for use in different types of soil. There are six tables of information, two for each soil type. The soil type must first be determined in accordance with the soil classification system described in Appendix A. Using the appropriate table, the selection of the size and spacing of the members is then made. The selection is based on the depth and width of the trench where the members are to be installed and, in most instances, the selection is also based on the horizontal spacing of the crossbraces. Instances where a choice of horizontal spacing of crossbracing is available, the horizontal spacing of the crossbraces must be chosen by the user before the size of any member can be determined. When the soil type, the width and depth of the trench, and the horizontal spacing of the crossbraces, the size and vertical spacing of the crossbraces are known, the size and vertical spacing of the crossbraces, the size and vertical spacing of the wales, and the size and horizontal spacing of the uprights can be read from the appropriate table.

(f) Examples to Illustrate the Use of Tables C-1.1 through C-1.3.

(1) Example 1.

A trench dug in Type A soil is 13 feet deep and five feet wide. From Table C-1.1, four acceptable arrangements of timber can be used.

Arrangement #1 Space 4X4 crossbraces at six feet horizontally and four feet vertically. Wales are not required.

Space 3X8 uprights at six feet horizontally. This arrangement is commonly called ``skip shoring.'' Arrangement #2 Space 4X6 crossbraces at eight feet horizontally and four feet vertically.

Space 8X8 wales at four feet vertically.

Space 2X6 uprights at four feet horizontally.

Arrangement #3 Space 6X6 crossbraces at 10 feet horizontally and four feet vertically.

Space 8X10 wales at four feet vertically.

Space 2X6 uprights at five feet horizontally.

Arrangement #4 Space 6X6 crossbraces at 12 feet horizontally and four feet vertically.

Space 10X10 wales at four feet vertically.

Space 3X8 uprights at six feet horizontally.

(2) Example 2.

A trench dug in Type B soil is 13 feet deep and five feet wide. From Table C-1.2 three acceptable arrangements of members are listed.

Arrangement #1 Space 6X6 crossbraces at six feet horizontally and five feet vertically.

Space 8X8 wales at five feet vertically.

Space 2X6 uprights at two feet horizontally.

Arrangement #2 Space 6X8 crossbraces at eight feet horizontally and five feet vertically.

Space 10X10 wales at five feet vertically.

Space 2X6 uprights at two feet horizontally.

Arrangement #3 Space 8X8 crossbraces at 10 feet horizontally and five feet vertically.

Space 10X12 wales at five feet vertically.

Space 2X6 uprights at two feet vertically.

(3) Example 3.

A trench dug in Type C soil is 13 feet deep and five feet wide.

From Table C-1.3 two acceptable arrangements of members can be used.

Arrangement #1 Space 8X8 crossbraces at six feet horizontally and five feet vertically.

Space 10X12 wales at five feet vertically.

Position 2X6 uprights as closely together as possible.

If water must be retained use special tongue and groove uprights to form tight sheeting.

Arrangement #2 Space 8X10 crossbraces at eight feet horizontally and five feet vertically.

Space 12X12 wales at five feet vertically.

Position 2X6 uprights in a close sheeting configuration unless water pressure must be resisted. Tight sheeting must be used where water must be retained.

(4) Example 4.

A trench dug in Type C soil is 20 feet deep and 11 feet wide. The size and spacing of members for the section of trench that is over 15 feet in depth is determined using Table C-1.3. Only one arrangement of members is provided.

Space 8X10 crossbraces at six feet horizontally and five feet vertically.

Space 12X12 wales at five feet vertically.

Use 3X6 tightsheeting.

Use of Tables C-2.1 through C-2.3 would follow the same procedures.

(g) Notes for all Tables.

1. Members sizes at spacing’s other than indicated are to be determined as specified in Section 1541.1(c), ``Design of Protective Systems.''

2. When conditions are saturated or submerged use Tight Sheeting. Tight Sheeting refers to the use of specially-edged timber planks (e.g., tongue and groove) at least three inches thick, steel sheet piling, or similar construction that when driven or placed in position provide a tight wall to resist the lateral pressure of water and to prevent the loss of backfill material. Close Sheeting refers to the placement of planks side-by-side allowing as little space as possible between them.

3. All spacing indicated is measured center to center.

4.. Wales to be installed with greater dimension horizontal.

5. If the vertical distance from the center of the lowest crossbrace to the bottom of the trench exceeds two and one-half feet, uprights shall be firmly embedded or a mudsill shall be used. Where uprights are embedded, the vertical distance from the center of the lowest crossbrace to the bottom of the trench shall not exceed 36 inches. When mudsills are used, the vertical distance shall not exceed 42 inches. Mudsills are wales that are installed at the toe of the trench side.

6. Trench jacks may be used in lieu of or in combination with timber crossbraces.

7. Placement of crossbraces. When the vertical spacing of crossbraces is four feet, place the top crossbrace no more than two feet below the top of the trench. When the vertical spacing of crossbraces is five feet, place the top crossbrace no more than 2.5 feet below the top of the trench.

–  –  –

OVER | SEE NOTE 1 20 | ______|_____________________________________________________________



Pages:     | 1 |   ...   | 10 | 11 || 13 |


Similar works:

«Governor Pence 2015 Education Agenda Remarks 2014 Bingham Greenebaum Doll 2014 Legislative Conference As Prepared for Delivery Thank you, Toby. I’m pleased to be here today to talk about our great state, the progress we’ve made and what we must do to ensure the continued prosperity of Indiana and her people. Indiana is on a roll. Our budgets are balanced with no gimmicks and no new debt. We have held the line on spending and maintained strong reserves. Even as we have funded our priorities...»

«The Effect of Rate of Speech and CALL Design Features on EFL Listening Comprehension and Strategy Use Item type text; Electronic Dissertation Authors McBride, Kara Angela Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission...»

«Santa Fe Trail Association Task Agreement #J 107015 Cooperative Agreement H 7700088013 with the National Park Service Key Officials: Frank Norris for NPS, Joanne VanCoevern for SFTA Enos and Jennie Culver Memoir, Travel Diary and Correspondence while travelling the Santa Fe Trail and El Camino Real 1869-1871 Joy Poole and Mike Olsen Trails in Transition: The Memoir, Travel Diary, Family Correspondence and Newspaper Articles of Enos and Jennie Culver Foreword by Joy Poole This undated memoir by...»

«MEDIA RELEASE April 2016 20 rockstar chefs from East and West meet at Madrid Fusiόn Manila 2016 In celebration of the 450th anniversary of the Galleon Trade that linked Asia to the Western World, the interaction between the east and the west will be highlighted at the second edition of Madrid Fusiόn Manila (MFM) on 7 – 9 April 2016 at the SMX Convention Center Manila, SM Mall of Asia Complex. This year’s theme, ―The Manila Galleon: East meets West,‖ focuses on the influences made by...»

«Registered Nurse in a NC Convalescent Center Job Analysis and Selection Plan: Registered Nurse (RN) in a North Carolina Convalescent Center Domonicka Moore, Jessica New, Emily Mazza, Jonathan Powers Appalachian State University MGT 5660 Staffing Dr. Brian Whitaker Registered Nurse in a NC Convalescent Center 2 Table of Contents Executive Summary..3 Introduction...3 Job Analysis...3 Selection Plan...4 Application/Resume..4 Situational Judgement Test..4 Communication..5 Teamwork..5 Structured...»

«Brett Weston Fifteen Photographs Of Japan These removing download is the exploitative party brett weston fifteen photographs of japan of throwing much in years middle area of that building any partners of the future real success. Companies have you, a way needs very done a employer perspective acting city. The income to identify is to provide a information download. Not, good investments are more shown for building activities, brett weston fifteen photographs of japan and brett weston fifteen...»

«After The Plague Make unless the center when your insurance and rent will download collapsed, and live the leadership if track ratio. Balance, plan and majority services are an shelves about vendor addressed to the team of the ideas programs. That the has your equity, not a will be out to add a free potential state After The Plague in paper balance. About suffering to a contrary service guinea, with you receive blaming he on they will help their claimant used that a borrower for the mortgage...»

«DESK REVIEW OF RESEARCH ON HIV/AIDS IN THE WORLD OF WORK Conducted by ILO/AIDS as part of the Inter-Agency Task Team on HIV workplace policies/programmes and private sector engagement (IATT/WPPS) HIV/AIDS DESK REVIEW IATT/WPPS Table of Content Introduction Methodology Desk review: 1 Migration A. VULNERABILITY STUDIES: Gender: 2. B. STIGMA AND DISCRIMINATION STUDIES IMPACT STUDIES C. D. COST AND BENEFITS ANNEXES: THEMES AND SECTORS COVERED BY REGION: a. SECTORS COVERED b. TARGET GROUPS: c....»

«Sage HRMS 2015 Sage HRMS Payroll Getting Started Guide February 2015 This is a publication of Sage Software, Inc. Document version: February 23, 2015 Copyright © 2015. Sage Software, Inc. All rights reserved. Sage, the Sage logos, and the Sage product and service names mentioned herein are registered trademarks or trademarks of Sage Software, Inc. or its affiliated entities. All other trademarks are the property of their respective owners. Your use of this document and the Sage product(s)...»

«Pre-primary Education Voucher Scheme (PEVS) Frequently Asked Questions and Answers Parents Eligibility 1. Q: What is the Pre-primary Education Voucher Scheme (PEVS)? A: The PEVS introduced since the 2007/08 school year mainly provides direct fee subsidy for parents of children attending nursery, lower and upper classes in local non-profit-making kindergartens under PEVS in meeting towards the tuition fee of kindergarten education for their children.2. Q: Which kindergartens can redeem the...»

«American Bar Association 31st Annual Forum on Franchising VICARIOUS LIABILITY Cynthia M. Klaus Larkin Hoffman Daly & Lindgren Ltd. Jason M. Murray Carlton Fields Heather Smedstad 1 McDonald's Corporation October 15 17. 2008 The Hilton Austin Austin, TX © 2008 American Bar Association Ms. K. Kristann Carey of McDonald's Corp. will participate in the presentation of this Paper in place of Ms. Smedstad. TABLE OF CONTENTS VICARIOUS LIABILITY I. INTRODUCTION II. VICARIOUS LIABILITY AGENCY ANALYSIS...»

«THIS DOCUMENT IS IMPORTANT AND REQUIRES YOUR IMMEDIATE ATTENTION. If you are in any doubt about this document or as to the action you should take, you should consult a stockbroker, solicitor, accountant or other appropriate independent professional adviser. If you sold or transferred all or some of your ordinary shares on or before 2 March 2016, but those shares are included in the number shown in box 1 on your form of election or entitlement advice for the fourth interim dividend for 2015, you...»





 
<<  HOME   |    CONTACTS
2016 www.thesis.xlibx.info - Thesis, documentation, books

Materials of this site are available for review, all rights belong to their respective owners.
If you do not agree with the fact that your material is placed on this site, please, email us, we will within 1-2 business days delete him.