Asce 41 - Seismic Rehabilitation Of Existing Buildings z1g22
This document was ed by and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this report form. Report 2z6p3t
Overview 5o1f4z
& View Asce 41 - Seismic Rehabilitation Of Existing Buildings as PDF for free.
More details 6z3438
- Words: 1,998
- Pages: 70
ASCE 41 Seismic Rehabilitation of Existing Buildings
Presentation Topics: 1.
2. 3. 4. 5. 6.
How to define a Rehabilitation Objective per ASCE 41. Data Collection and Testing. Analysis Requirements. Modeling. Results Evaluation. Design and Rehabilitation.
What is ASCE 41?
It is mainly a combination of two FEMA documents: FEMA 356 – Technical Requirements for Seismic Rehabilitation of Buildings – Superseded by ASCE 41. FEMA 274 – NEHRP Commentary on the Guidelines for Seismic Rehabilitation of Buildings. ASCE 31 – Seismic Evaluation of Existing Buildings (ing document).
Why use ASCE 41?
To improve the seismic performance of any existing structure: ASCE 41 addresses rehabilitation of Architectural, Mechanical, Electrical and Structural systems. ASCE 41 can be used to rehabilitate historic structures. Where performance based rehabilitations are desired.
What is required for the Rehabilitation? 1.
2.
A Seismic Evaluation must be performed to identify deficiencies to be rehabilitated. ASCE 31 (Formerly FEMA 310) can be used for the evaluation. Define the Rehabilitation Objective - a combination of a Target Building Performance Level, an Earthquake Hazard Level, and an Objective Classification.
Target Building Performance: 1.
Structural Performance Level: ASCE 41 1.5.1 and Tables C1-2,3, & 4 define six levels: • Immediate Occupancy (S-1) • Damage Control Range (S-2) • Life Safety (S-3) • Limited Safety Range (S-4) • Collapse Prevention (S-5) • Not Considered (S-6) Tables C1-2 to C1-4 defines typical damage that accompany these levels.
Target Building Performance: Damage increases
Primary component – Any structural element that resists loads and deformations from seismic loads in addition to gravity loads. Secondary component – any element that resists deformations + gravity loads.
Target Building Performance: 1.
Nonstructural Performance Level: ASCE 41 1.5.2 and Tables C1-5 & 6 define five levels: • Operational (N-A) • Immediate Occupancy (N-B) • Life Safety (N-C) • Hazards Reduced (N-D) • Not Considered (N-E) Tables C1-5 & 6 define typical damage that accompany these levels.
Target Building Performance: Damage increases
Target Building Performance:
Example: N-A + S-1 yields 1-A Target Building Performance designation.
Earthquake Hazard Level: BSE – 2 Event: An earthquake with a 2% probability in 50 years of being exceeded. This is an earthquake with a 2500 year reoccurrence period or the MCE as defined in ASCE 7 or IBC. BSE – 1 Event: An earthquake with a 10% probability in 50 years of being exceeded. This is an earthquake with a 500 year reoccurrence period or the design event defined in ASCE 7 or IBC. BSE – Basic Service Earthquake
QUIZ ???: What document did ASCE 41 replace?
The History of Future Architecture.
Texas Architect.
FEMA 356.
Rehabilitation Objective Classes: Basic Safety Objective – typical for Ancillary structures (Office buildings) 2. Enhanced Rehabilitation Objective – typical for Critical or Essential structures (Hospitals, Fire stations, Police stations) 3. Limited Rehabilitation Objective – (Other less critical structures) You and your client define the req’d Class. 1.
Rehabilitation Objective:
Now that you have defined you Rehabilitation Objective what is next?:
Data Collection Analysis Requirements Modeling Results Evaluation Design and Rehabilitation
Data Collection: 1. 2.
From existing plans OR From a comprehensive testing program
Requirements depend on your Rehabilitation Objective and the information available to you from existing plans. Testing is needed to obtain enough information to build the linear or nonlinear model. Material testing to modeling can be very expensive and time consuming.
Data Collection:
Knowledge Factor – scale factor to reduce element capacity due to uncertainty in element composition. Comprehensive plan required when exist. dwgs don’t have enough information.
Testing:
Wall thickness and wall to column connection check.
Testing:
Steel coupons and clay tile wall sample for testing. Use ASCE 41 to determine number of tests and locations.
Testing:
Core drilling of foundation to determine concrete material properties.
Testing:
Concrete cores for compression testing.
Testing:
In-situ shear test of a clay tile wall.
Testing:
40” x 40”
Flexural test of clay tile to determine out of plane bending capacity.
Testing:
Compression test of clay tile sample.
Analysis Options: 1.
Linear static - LSP (considered the least accurate) Linear model subject to lateral loading determined by ASCE 41. Similar to IBC / ASCE 7 equivalent lateral force method. Allowed only for structures without irregularities defined in ASCE 41 (basically the same irregularity types defined in ASCE 7). Allowed only for some structures which do not have any irregularities defined for the NSP.
Analysis Options: 2.
Linear dynamic - LDP (considered more accurate than the LSP) Linear model subjected to response spectral or time history loading. Allowed only for some structures which do not have any irregularities defined for the NSP. V = 0.85 VLSP
Analysis Options: 3.
Nonlinear static – NSP (considered accurate enough for most structures) Structural model with nonlinear material behavior assigned to structural elements pushed to a static displacement defined by ASCE 41. This is called the Target Displacement. Can be required by your client. V = 0.7 VLSP
Analysis Options:
Required if any of the following are true:
Buildings with non-orthogonal lateral system. Building with a vertical stiffness irregularity. Building which has a torsional stiffness irregularity in any story. When the first mode period is more than 3.5Ts with Ts = S1 / Ss p. 26. Any structure where the horizontal dimension of any story exceeds that of an adjacent story by 1.4.
Analysis Options: 4.
Nonlinear time history - NDP (considered the most accurate) Structural model with nonlinear material behavior assigned to structural elements subjected to an earthquake time history loading. Required for certain structures including those when R> Rmax. R is a parameter related to the structures’ capacity / the seismic demand. Permitted for all structures and a third party review may be required for this analysis method.
QUIZ ???: What should you do if the existing plans do not have information on the existing materials in the building? A.
Ask the Architect for more fee?
B.
Initiate a comprehensive testing program?
C.
Analyze the structure using the Nonlinear Dynamic Procedure?
Nonlinear Modeling for NSP: A model that considers material nonlinearity in all elements which comprise it including: 1.
Likely plastic hinge regions modeled with FEMA 356 nonlinear hinges.
2.
Material stress strain relationships assigned to concrete, steel, masonry, Fiber Reinforced Polymer (FRP) and clay tile structural elements (etc).
Material Stress-Strain Relations as defined by ASCE 41:
Curve 1 – Ductile material with a post yield residual strength (deformation controlled).
Curve 2 – Ductile material without post yield residual strength (deformation controlled).
Curve 3 – Brittle material (force controlled). HCT in shear. Steel
HCT in compress.
Force-Deformation Relations for Concrete (Chapter 6 ASCE 41):
Q – applied load. Qy – yield force. a, b, c, and d defined by ASCE 41. The Engineer must use these relationships along with definitions for points a, b, c, and d to define material nonlinearity.
Nonlinear Modeling for NSP: Acceptance Criteria – Concrete Hinges:
More stringent reqs
C – conforming transverse steel (ties). NC – Nonconforming transverse steel.
Nonlinear Modeling for NSP: FEMA 356 Hinges - Concrete:
Nonlinear Modeling for NSP: Steel (Type 1 Curve):
Ductile Range
Nonlinear Modeling for NSP: Concrete (Type 3 Curve):
Brittle
Nonlinear Modeling for NSP: Clay Tile – Shear Only (From Judgment and published research. Allowed by ASCE 41 C1.2)
Zero tension Shear yield Comp
Shear failure
Nonlinear Modeling for NSP: Clay Tile – Compression (Type 3 Curve):
E2 = 0.1 E1
E2 Brittle
E1
Programs:
SAP 2000 Advanced
STAAD Pro Nonlinear
PERFORM
ANSYS
These programs are expensive per license and require a “strong” computer to run the models. Example 12 NL load combos takes 20 hours to solve.
QUIZ ???: The following represents what kind of material behavior?
A.
Brittle.
B.
Elastic-Perfect Plastic.
C.
Ductile.
Nonlinear Modeling Process:
For a Nonlinear Static Model you are basically in need of establishing the pushover curve for the structure and ing that R < Rmax. This is done by: 1.
Defining the Target Displacement for the structure at the control node:
Co – factor to equate a SDOF system to actual bldg. C1 – inelastic scale factor. Te – effective first mode period. C2 – factor for pinched hystersis + cyclic strength degradation.
Nonlinear Modeling Process: 2.
Push the model, using inertial forces applied to the model in proportion to the first mode shape, to the target displacement and define the Static Pushover Curve for the building. The target displacement will vary for each major direction of the structure. This process is iterative and time consuming.
Nonlinear Modeling Process: 3.
Define R based on the results of the push over analysis. R is a measure of system stability. Rmax is a measure of system ductility.
Cm – mass effective in the first mode and Vy is the structure first yield force. y – yield displacement. d – target disp. Rmax – roughly the same as R from ASCE 7. Vy – structure first yield, W str weight, Sa – response spectra acceleration at Te.
Nonlinear Modeling Process: 4.
The target displacement is dependent on the level of seismic activity expected at your site, the soil properties of your site, mass effective in the first mode, and amount of viscous damping capacity of your structure.
Static Pushover Curve: Actual Struct performance
Vd – maximum capacity
Static Pushover Curve:
Structure capacity curve
ASCE Bilinear pushover curve
kips
inches
Example – Simple Nonlinear Model: Description: 2 – story reinforced concrete structure with r/c second floor and roof. Material nonlinearity assigned to the concrete and reinforcing steel. Plastic hinge zones modeled with FEMA 356 hinges. Modeling and analysis completed in SAP 2000 Advanced for a BSE-2 event in Albuquerque, NM.
24’ x 30’ bays with 2 – 12’ tall stories, 18” x 18” columns, and 6” thick diaphragms at the roof and second floor.
Nonlinear Results Evaluation: 1.
R < Rmax
2.
Individual component behavior is within the acceptance criteria limitations for that component. This is dependent on the loaddeformation limits prescriptive to the Rehabilitation Objective. (i.e. IO, LS, )
3.
Individual component behavior is within the limits defined by the governing code using load combinations and factors defined by ASCE 41. (i.e. = 1.0)
Rehabilitation Options:
Addition of new concrete shear walls
Use of Fiber Reinforced Polymer laminates to strengthen masonry, unreinforced clay tile, or concrete .
Add steel bracing
Improve connection capacities
Reduce structure mass
Global stiffening
Rehabilitation Options: Fiber Reinforced Polymers Pre-cured system => BASF. Is a the process
of installing FRP “belts” or strips to the substrate. Strips are fully cured prior to being laminated to the substrate with epoxy. Wet layup system => Fyfe. Is the process of
installing FRP fabric to the substrate following saturation of the fabric with epoxy. This process is “like paper mache”.
Rehabilitation Options: Fiber Reinforced Polymers
FRP can add an additional 25% to 30% to column capacities.
FRP Pull Test
ASTM D4541
Rehabilitation Options: Fiber Reinforced Polymers
FRP can add an additional 50% to beam strength.
Rehabilitation Options: Fiber Reinforced Polymers
MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
Rehabilitation Options: Fiber Reinforced Polymers
MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
Fiber direction – FRP is typically a uniaxial material MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
Rehabilitation Options: Fiber Reinforced Polymers
Nueces Courthouse – Corpus Christi, TX
Rehabilitation Options: Fiber Reinforced Polymers
Rehabilitation Options: Fiber Reinforced Polymers
FRP pre-cured laminates can give you about 10 klf (5 klf for wet lay ups) per side of additional shear capacity.
Rehabilitation Options: Fiber Reinforced Polymers
Fiber direction – FRP is typically a uniaxial material
Rehabilitation Options: FRP Details
Rehabilitation Options: FRP Details
Rehabilitation Options: FRP Details
FRP Suppliers and Codes:
BASF
FYFE
SIKA
ACI 440.7
QUESTIONS???
Presentation Topics: 1.
2. 3. 4. 5. 6.
How to define a Rehabilitation Objective per ASCE 41. Data Collection and Testing. Analysis Requirements. Modeling. Results Evaluation. Design and Rehabilitation.
What is ASCE 41?
It is mainly a combination of two FEMA documents: FEMA 356 – Technical Requirements for Seismic Rehabilitation of Buildings – Superseded by ASCE 41. FEMA 274 – NEHRP Commentary on the Guidelines for Seismic Rehabilitation of Buildings. ASCE 31 – Seismic Evaluation of Existing Buildings (ing document).
Why use ASCE 41?
To improve the seismic performance of any existing structure: ASCE 41 addresses rehabilitation of Architectural, Mechanical, Electrical and Structural systems. ASCE 41 can be used to rehabilitate historic structures. Where performance based rehabilitations are desired.
What is required for the Rehabilitation? 1.
2.
A Seismic Evaluation must be performed to identify deficiencies to be rehabilitated. ASCE 31 (Formerly FEMA 310) can be used for the evaluation. Define the Rehabilitation Objective - a combination of a Target Building Performance Level, an Earthquake Hazard Level, and an Objective Classification.
Target Building Performance: 1.
Structural Performance Level: ASCE 41 1.5.1 and Tables C1-2,3, & 4 define six levels: • Immediate Occupancy (S-1) • Damage Control Range (S-2) • Life Safety (S-3) • Limited Safety Range (S-4) • Collapse Prevention (S-5) • Not Considered (S-6) Tables C1-2 to C1-4 defines typical damage that accompany these levels.
Target Building Performance: Damage increases
Primary component – Any structural element that resists loads and deformations from seismic loads in addition to gravity loads. Secondary component – any element that resists deformations + gravity loads.
Target Building Performance: 1.
Nonstructural Performance Level: ASCE 41 1.5.2 and Tables C1-5 & 6 define five levels: • Operational (N-A) • Immediate Occupancy (N-B) • Life Safety (N-C) • Hazards Reduced (N-D) • Not Considered (N-E) Tables C1-5 & 6 define typical damage that accompany these levels.
Target Building Performance: Damage increases
Target Building Performance:
Example: N-A + S-1 yields 1-A Target Building Performance designation.
Earthquake Hazard Level: BSE – 2 Event: An earthquake with a 2% probability in 50 years of being exceeded. This is an earthquake with a 2500 year reoccurrence period or the MCE as defined in ASCE 7 or IBC. BSE – 1 Event: An earthquake with a 10% probability in 50 years of being exceeded. This is an earthquake with a 500 year reoccurrence period or the design event defined in ASCE 7 or IBC. BSE – Basic Service Earthquake
QUIZ ???: What document did ASCE 41 replace?
The History of Future Architecture.
Texas Architect.
FEMA 356.
Rehabilitation Objective Classes: Basic Safety Objective – typical for Ancillary structures (Office buildings) 2. Enhanced Rehabilitation Objective – typical for Critical or Essential structures (Hospitals, Fire stations, Police stations) 3. Limited Rehabilitation Objective – (Other less critical structures) You and your client define the req’d Class. 1.
Rehabilitation Objective:
Now that you have defined you Rehabilitation Objective what is next?:
Data Collection Analysis Requirements Modeling Results Evaluation Design and Rehabilitation
Data Collection: 1. 2.
From existing plans OR From a comprehensive testing program
Requirements depend on your Rehabilitation Objective and the information available to you from existing plans. Testing is needed to obtain enough information to build the linear or nonlinear model. Material testing to modeling can be very expensive and time consuming.
Data Collection:
Knowledge Factor – scale factor to reduce element capacity due to uncertainty in element composition. Comprehensive plan required when exist. dwgs don’t have enough information.
Testing:
Wall thickness and wall to column connection check.
Testing:
Steel coupons and clay tile wall sample for testing. Use ASCE 41 to determine number of tests and locations.
Testing:
Core drilling of foundation to determine concrete material properties.
Testing:
Concrete cores for compression testing.
Testing:
In-situ shear test of a clay tile wall.
Testing:
40” x 40”
Flexural test of clay tile to determine out of plane bending capacity.
Testing:
Compression test of clay tile sample.
Analysis Options: 1.
Linear static - LSP (considered the least accurate) Linear model subject to lateral loading determined by ASCE 41. Similar to IBC / ASCE 7 equivalent lateral force method. Allowed only for structures without irregularities defined in ASCE 41 (basically the same irregularity types defined in ASCE 7). Allowed only for some structures which do not have any irregularities defined for the NSP.
Analysis Options: 2.
Linear dynamic - LDP (considered more accurate than the LSP) Linear model subjected to response spectral or time history loading. Allowed only for some structures which do not have any irregularities defined for the NSP. V = 0.85 VLSP
Analysis Options: 3.
Nonlinear static – NSP (considered accurate enough for most structures) Structural model with nonlinear material behavior assigned to structural elements pushed to a static displacement defined by ASCE 41. This is called the Target Displacement. Can be required by your client. V = 0.7 VLSP
Analysis Options:
Required if any of the following are true:
Buildings with non-orthogonal lateral system. Building with a vertical stiffness irregularity. Building which has a torsional stiffness irregularity in any story. When the first mode period is more than 3.5Ts with Ts = S1 / Ss p. 26. Any structure where the horizontal dimension of any story exceeds that of an adjacent story by 1.4.
Analysis Options: 4.
Nonlinear time history - NDP (considered the most accurate) Structural model with nonlinear material behavior assigned to structural elements subjected to an earthquake time history loading. Required for certain structures including those when R> Rmax. R is a parameter related to the structures’ capacity / the seismic demand. Permitted for all structures and a third party review may be required for this analysis method.
QUIZ ???: What should you do if the existing plans do not have information on the existing materials in the building? A.
Ask the Architect for more fee?
B.
Initiate a comprehensive testing program?
C.
Analyze the structure using the Nonlinear Dynamic Procedure?
Nonlinear Modeling for NSP: A model that considers material nonlinearity in all elements which comprise it including: 1.
Likely plastic hinge regions modeled with FEMA 356 nonlinear hinges.
2.
Material stress strain relationships assigned to concrete, steel, masonry, Fiber Reinforced Polymer (FRP) and clay tile structural elements (etc).
Material Stress-Strain Relations as defined by ASCE 41:
Curve 1 – Ductile material with a post yield residual strength (deformation controlled).
Curve 2 – Ductile material without post yield residual strength (deformation controlled).
Curve 3 – Brittle material (force controlled). HCT in shear. Steel
HCT in compress.
Force-Deformation Relations for Concrete (Chapter 6 ASCE 41):
Q – applied load. Qy – yield force. a, b, c, and d defined by ASCE 41. The Engineer must use these relationships along with definitions for points a, b, c, and d to define material nonlinearity.
Nonlinear Modeling for NSP: Acceptance Criteria – Concrete Hinges:
More stringent reqs
C – conforming transverse steel (ties). NC – Nonconforming transverse steel.
Nonlinear Modeling for NSP: FEMA 356 Hinges - Concrete:
Nonlinear Modeling for NSP: Steel (Type 1 Curve):
Ductile Range
Nonlinear Modeling for NSP: Concrete (Type 3 Curve):
Brittle
Nonlinear Modeling for NSP: Clay Tile – Shear Only (From Judgment and published research. Allowed by ASCE 41 C1.2)
Zero tension Shear yield Comp
Shear failure
Nonlinear Modeling for NSP: Clay Tile – Compression (Type 3 Curve):
E2 = 0.1 E1
E2 Brittle
E1
Programs:
SAP 2000 Advanced
STAAD Pro Nonlinear
PERFORM
ANSYS
These programs are expensive per license and require a “strong” computer to run the models. Example 12 NL load combos takes 20 hours to solve.
QUIZ ???: The following represents what kind of material behavior?
A.
Brittle.
B.
Elastic-Perfect Plastic.
C.
Ductile.
Nonlinear Modeling Process:
For a Nonlinear Static Model you are basically in need of establishing the pushover curve for the structure and ing that R < Rmax. This is done by: 1.
Defining the Target Displacement for the structure at the control node:
Co – factor to equate a SDOF system to actual bldg. C1 – inelastic scale factor. Te – effective first mode period. C2 – factor for pinched hystersis + cyclic strength degradation.
Nonlinear Modeling Process: 2.
Push the model, using inertial forces applied to the model in proportion to the first mode shape, to the target displacement and define the Static Pushover Curve for the building. The target displacement will vary for each major direction of the structure. This process is iterative and time consuming.
Nonlinear Modeling Process: 3.
Define R based on the results of the push over analysis. R is a measure of system stability. Rmax is a measure of system ductility.
Cm – mass effective in the first mode and Vy is the structure first yield force. y – yield displacement. d – target disp. Rmax – roughly the same as R from ASCE 7. Vy – structure first yield, W str weight, Sa – response spectra acceleration at Te.
Nonlinear Modeling Process: 4.
The target displacement is dependent on the level of seismic activity expected at your site, the soil properties of your site, mass effective in the first mode, and amount of viscous damping capacity of your structure.
Static Pushover Curve: Actual Struct performance
Vd – maximum capacity
Static Pushover Curve:
Structure capacity curve
ASCE Bilinear pushover curve
kips
inches
Example – Simple Nonlinear Model: Description: 2 – story reinforced concrete structure with r/c second floor and roof. Material nonlinearity assigned to the concrete and reinforcing steel. Plastic hinge zones modeled with FEMA 356 hinges. Modeling and analysis completed in SAP 2000 Advanced for a BSE-2 event in Albuquerque, NM.
24’ x 30’ bays with 2 – 12’ tall stories, 18” x 18” columns, and 6” thick diaphragms at the roof and second floor.
Nonlinear Results Evaluation: 1.
R < Rmax
2.
Individual component behavior is within the acceptance criteria limitations for that component. This is dependent on the loaddeformation limits prescriptive to the Rehabilitation Objective. (i.e. IO, LS, )
3.
Individual component behavior is within the limits defined by the governing code using load combinations and factors defined by ASCE 41. (i.e. = 1.0)
Rehabilitation Options:
Addition of new concrete shear walls
Use of Fiber Reinforced Polymer laminates to strengthen masonry, unreinforced clay tile, or concrete .
Add steel bracing
Improve connection capacities
Reduce structure mass
Global stiffening
Rehabilitation Options: Fiber Reinforced Polymers Pre-cured system => BASF. Is a the process
of installing FRP “belts” or strips to the substrate. Strips are fully cured prior to being laminated to the substrate with epoxy. Wet layup system => Fyfe. Is the process of
installing FRP fabric to the substrate following saturation of the fabric with epoxy. This process is “like paper mache”.
Rehabilitation Options: Fiber Reinforced Polymers
FRP can add an additional 25% to 30% to column capacities.
FRP Pull Test
ASTM D4541
Rehabilitation Options: Fiber Reinforced Polymers
FRP can add an additional 50% to beam strength.
Rehabilitation Options: Fiber Reinforced Polymers
MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
Rehabilitation Options: Fiber Reinforced Polymers
MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
Fiber direction – FRP is typically a uniaxial material MBrace system from BASF
Rehabilitation Options: Fiber Reinforced Polymers
Rehabilitation Options: Fiber Reinforced Polymers
Nueces Courthouse – Corpus Christi, TX
Rehabilitation Options: Fiber Reinforced Polymers
Rehabilitation Options: Fiber Reinforced Polymers
FRP pre-cured laminates can give you about 10 klf (5 klf for wet lay ups) per side of additional shear capacity.
Rehabilitation Options: Fiber Reinforced Polymers
Fiber direction – FRP is typically a uniaxial material
Rehabilitation Options: FRP Details
Rehabilitation Options: FRP Details
Rehabilitation Options: FRP Details
FRP Suppliers and Codes:
BASF
FYFE
SIKA
ACI 440.7
QUESTIONS???
Related Documents c2h70
Asce 41 - Seismic Rehabilitation Of Existing Buildings z1g22
November 2019 98
Asce - Sei 41-13 - Seismic Evaluation And Retrofit Of Existing Buildings - 10 Concrete - Indice 43412n
November 2019 548
Seismic Detailing Of Concrete Buildings 5o5i2k
October 2019 83
Target Seismic Performance Level Based On Asce 41-13.pdf 3f3y3z
April 2020 10
Asce 7-05 Seismic Provisions 1x446j
January 2023 0
Asce 7-10 Seismic Loading 6y261o
November 2019 71More Documents from "Babak Kamrani" 2v4i5c
Asce 41 - Seismic Rehabilitation Of Existing Buildings z1g22
November 2019 98
Mosaicism 5l591q
August 2021 0
6g3p1u
November 2019 50
Is The Brain A Digital Computer - John R. Searle.pdf soi
January 2022 0
Human Chromosome Nomenclature 6h5e1g
November 2019 36