The Structural Analysis and Performance
of
Wood Cellular Retaining Wall
{
作者:Bo-Yang Cheng
Chiang Wei
Min-Lang Lin
Far-Ching Lin
報告人:張健威
Order
1.Introduction
2.Test materials and methods
3.Result and dissussion
4.Conclusions
5.Other data
1.Introduction
Wooden constructions are energy saving and carbon dioxide
emission reduction products. Comparing with concrete constructions,
its energy consumption and carbon dioxide emission are lower. It is
also a recyclable bio-material which is easy to manufacture to the
environment, so it is often used for ecological technique especially
the treatment technology of side-slope in Taiwan.
Wooden
Concrete
1.Introduction
Wooden cellular retaining wall is a usual form of the slope structures. It is a
quite old engineering method, so there are many kinds of improving methods
developed. For example, “O&D method” was developed in Japan then
introduced in Taiwan. However, “O&D method＂ is still lack of the credible
strength and the accurate strength information, many users cannot fully trust
the safety of structures, so it can be only used for small scale dilapidation
slope engineering, causing the limitation of popularization.
2.Test materials and methods
2.1 STRUCTURAL ANALYSIS SOFTWARE
In the study, retaining wall structures is analyzed by computer matrix
analysis software, STAAD PRO 2005 , which developed by Bentleys
System Inc., U.S.A. and certified by civil engineers in Taiwan.
2.Test materials and methods
Figure 2: The front view of wooden retaining wall.( Unit : cm )
The side view of wooden retaining wall. (Standard unit figure) ( Unit : cm )
2.Test materials and methods
Figure 4: The top view of wooden retaining wall. (Standard unit figure) (Unit : cm )
2.Test materials and methods
2.2 SIMULATION MODEL
Material properties input in program were summarized as follows.
The specific gravity of Japan Cedar is 0.35
Moudulus of elasticty is 10Gpa
tension strength is 120 kgf / mm2
Backfill soil specific gravity is 1.8 t/m3
basement soil specific gravity is 1.9 t/m3
Concrete specific gravity is 2.3 t/m3
Except for considering the binding force and earthquake pressure of the back of
a wooden retaining wall, the safety factor of declination, slippage and basement
support force of wooden retaining wall should be figured out.
2.Test materials and methods
2.3 LOADING AND RESTRAIN CONDITIONS
The sizes of the first wooden retaining wall frame are hereunder.
The first frame length is 1.76m, width is 0.76 and height is 1.5m.
2.Test materials and methods
1.LAD SCREW WITHDRAWING TEST
The withdrawing test of lag screw was carried by universal testing
machine. During the test withdrawing strength verse displacement
was recorded in order to simulate a short member with, yield strength,
tensile strength, and stiffness. Its values will be input into STAAD
PRO 2005 to assume the module of tensile elasticity is the lengthways
structures of wooden retaining wall.
3.Result and dissussion
2.PRIMARY ANALYSIS RESULTS
According to the analysis results of STAAD PRO 2005, when the
model is forcing by linear force 1,000N from the z axial along the xdirection, the nodes at top show the maximum displacements. And the
middle parts near the fixed ends at the bottom of the model show the
maximum x-direction displacements.
3.Result and dissussion
Xh
Yv
Zh
Xmax
0.001
-0.006
0.098
Xmin
-0.001
0.006
0.098
Ymax
0.000
0.007
0.119
Ymin
0.000
-0.007
0.118
Zmax
0.000
0.007
0.119
Zmin
0.000
-0.005
0.000
Table 1 : The maximum and minimum displacements of nodes
Xh : x-direction horizontal displacement
Yv : y-direction vertical displacement
Zh : z-direction horizontal displacement
Unit : mm
4.Conclusions
1. When building a safe and credible slope construction, the design of
the wooden retaining wall about wall reaction forces, the whole
stability, structure cross-section stresses and stain should be
considered.
2.The treatment technology of side-slope is not immobile, everyone
should emulate the appropriate way to design and build a favourable
wooden retaining wall.
3. Making good use of creation to abound the diversiform
ecoenvironment and make sure the safety of the facility. It is the
impulsion of the eco-technology and engineering methods to a mature
stage.
5.補充資料
剜口接合
鐵絲接合
螞蝗釘接合
螺絲、螺栓接合
5.補充資料
 接合應用分析(常見缺失)
剜口接合
1.於預定搭接點以剜口
機械加工為深度
1.5~2cm之弧形凹槽，
以容納搭接材，形成
密接之接點。
2.剜口搭接可提供水平
抗剪強度，
3.藉重力產生自體穩定
機制，
4.為最常用的圓木搭接
型式。
螞蝗釘接合
1.以ㄇ字型螞蝗釘側向接合構材，
2.為較粗放之接合形式；
3.釘入深度較淺，
4.可能造成局部變位、沉陷或木料乾縮、開裂導
致鬆動。
4.施工容易為其優點。
國內案例
林區管理處
羅東林區管理處
工程地點
多望溪集水區
宜專一線
東勢林區管理處 大雪山林道邊坡
新竹林區管理處 大溪區69林班崩塌地
八卦山保安林地
南投林區管理處
合和集水區上游野溪
腦寮溪
森林鐵路崩塌地
屏東林區管理處 錦屏林道
花蓮林區管理處 白鮑溪
嘉義林區管理處
應用工法
木格框擋土牆、O&D工法木格框
擋土牆、入口意象、導覽解說牌
木格框節制壩、木格框擋土牆
擋土柵、駁坎、觀景平台、導覽
解說牌
打木樁編柵
擋土牆、擋土柵、坡面保護工、
節制壩、護岸、排水溝、集水框
工、護欄、步道、解說平台、警
示牌、導覽解說牌、入口意象
節制壩、固床工、消能工、護岸、
解說平台、入口意象
木格籠擋土牆
木格籠擋土牆
木格柵擋土柵
木格籠擋土牆
5.補充資料
彰化廟前坑示範區
1.堆積式擋土牆
2.木排樁護坡
3.組合式檔土柵
4.仿校倉式擋土牆
5.堆疊格框式擋土牆
6.連續木排樁
7.連續木排樁(未去皮)
8.木製節制壩與排水溝
9.過水便橋
5.補充資料
 定期檢查
1. 目視檢測方法
 部分木材變形- 從整體木構造檢視木構架是否彎曲、
變形、歪斜或位移等形況。
 部分木材受損- 從構件外觀檢視是否有乾縮縱裂的 受外力(木本植物生長)劈裂
現象，或是受外力造成的劈裂。
 可見菌類- 檢視是否遭到霉菌孳息、白腐或褐腐現
象。
 蟻類活動跡象- 觀察構件表面是否有蟻路、蟻巢、
白蟻蛀蝕痕跡等。
2. 觸摸調查方法-以手指觸摸調查，有腐朽情形時， 遭霉菌孳息、及蟻類蛀蝕
會有軟化之感覺，再確實腐朽之部分可以錐形物、
起子等插入調查。
3. 敲打調查方法-木槌或鐵槌敲打調查，如有腐朽情
況時，與建全部位比較時會有音鈍、彈力較小之
情形。
鐵槌敲打調查
5.補充資料
蟻害
腐朽
變形
變形
變色腐朽
變色腐朽
Thank you for listening!