DB43/T 2280-2021 公路高液限土路基设计与施工技术规范

ICS93.080

CCSP66

43

湖南省地方标准

DB43/T2280—2021

公路高液限土路基设计与施工技术规范

Technicalspecificationsfordesignandconstructionof

highwaysubgradeofhighliquidlimitsoil

2021-12-29发布2022-03-29实施

湖南省市场监督管理局发布

DB43/T2280—2021

目次

前言························································································································Ⅲ

引言························································································································Ⅴ

1范围·····················································································································1

2规范性引用文件······································································································1

3术语和定义············································································································1

4符号和缩略语·········································································································2

5勘察·····················································································································2

5.1一般规定·········································································································2

5.2初步勘察·········································································································3

5.3详细勘察·········································································································5

6设计·····················································································································7

6.1一般规定·········································································································7

6.2填方路基设计···································································································7

6.3挖方路基设计···································································································9

6.4路基边坡稳定性分析························································································11

6.5边坡防护与加固设计························································································12

7施工···················································································································15

7.1一般规定·······································································································15

7.2填方路基施工·································································································16

7.3挖方路基施工·································································································17

7.4边坡防护与加固施工························································································18

8监测···················································································································19

8.1一般规定·······································································································19

8.2高填路基监测·································································································19

8.3深挖路基边坡监测···························································································19

附录A（资料性）湖南省高液限土分布········································································21

附录B（规范性）湿法重型击实试验···········································································23

B.1目的和适用范围······························································································23

B.2仪器设备·······································································································23

B.3试验步骤·······································································································24

附录C（规范性）吸附结合水含量试验········································································25

C.1目的和适用范围······························································································25

C.2仪器设备·······································································································25

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C.3试样制备·······································································································25

C.4试验步骤·······································································································25

C.5结果整理·······································································································26

附录D（规范性）高液限土路基刚度补偿层设计方法······················································27

D.1目的和适用范围······························································································27

D.2操作步骤·······································································································27

D.3刚度补偿层设计诺谟图的使用说明······································································31

附录E（规范性）高液限土路基PFWD回弹模量反算方法·················································32

E.1目的和适用范围······························································································32

E.2功能和数据准确度···························································································32

E.3运行环境·······································································································32

E.4运行说明·······································································································32

E.5建议的软件源程序···························································································32

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前言

本文件按照GB/T1.1—2020《标准化工作导则第1部分：标准化文件的结构和起草规则》的规

定起草。

请注意本文件的某些内容可能涉及专利。本文件的发布机构不承担识别专利的责任。

本文件由湖南省交通运输厅提出并归口。

本文件起草单位：长沙理工大学、湖南省交通规划勘察设计院有限公司、湖南省交通科学研究院有

限公司、创辉达设计股份有限公司、中南大学。

本文件主要起草人：郑健龙、张锐、胡惠华、彭立、郑祖恩、张军辉、肖燕、杨相展、刘文劼、胡

新红、李志勇、刘维正、王颖、肖宇鹏。

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引言

为指导湖南省公路高液限土路基设计与施工，保证工程质量，节约资源，保护环境，制定本文件。

本文件制定的指导思想：突出安全、耐久、环保等要求，注重路基的强度和稳定；贯彻节约资源、

保护环境的工程建设指导原则，合理利用高液限土填料；充分总结近二十年来湖南省及其气候相似地区

公路高液限土路基设计和施工技术，积极吸收成熟可靠的新技术、新工艺、新材料；力求技术先进、指

标合理、可操作性强，体现湖南省公路高液限土路基设计与施工技术的进步，并适度超前。

本文件的主要技术内容涵盖了公路高液限土路基勘察、设计和施工的全过程，分为8章：1总则，

2规范性引用文件，3术语和定义，4符号和缩略语，5勘察，6设计，7施工，8监测；5个附录：

附录A湖南省高液限土分布，附录B湿法重型击实试验，附录C吸附结合水含量试验，附录D高液限

土路基刚度补偿层设计方法，附录E高液限土路基PFWD回弹模量反算方法。

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公路高液限土路基设计与施工技术规范

1范围

1.1本文件规定了湖南省公路高液限土路基勘察、设计、施工和监测等技术要求。

1.2本文件适用于湖南省各等级新建和改扩建公路的高液限土路基设计与施工。当高液限土判定为膨

胀土时，应按现行国家和行业规范中膨胀土的相关规定进行路基设计与施工。

2规范性引用文件

下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。其中，注日期的引用文件，

仅该日期对应的版本适用于本文件；不注日期的引用文件，其最新版本（包括所有的修改单）适用于本

文件。

JTGC20公路工程地质勘察规范

JTGD30公路路基设计规范

JTG/TD32公路土工合成材料应用技术规范

JTG/T3610公路路基施工技术规范

JTG3430公路土工试验规程

JTG3450公路路基路面现场测试规程

3术语和定义

下列术语和定义适用于本文件。

3.1

高液限土highliquidlimitsoil

液限（100g锥试验）大于50％的细粒土。

（来源：JTGD30—2015，2.1.16）

3.2

湿法击实试验wetcompactiontest

采集5个以上的天然含水率土样，分別晾干至所需的不同含水率，然后按常规法进行的击实试验。

3.3

湿法CBR与含水率的关系曲线relationshipcurveofCaliforniaBearingRatioandwatercontent

basedonwetcompactiontests

结合湿法击实试和浸水CBR试验获得的CBR随初始含水率变化的曲线。

3.4

稠度consistency

表征土体软硬程度的指标，为液限和含水率之差与液限和塑限之差的比值。

3.5

路基平衡含水率equilibriumwatercontentofsubgrade

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在大气和地下水长期影响下，路基湿度达到相对稳定状态时路基的含水率。

3.6

吸附结合水adsorbedboundwater

密度大于1.0g/cm3且具有类固相性质的弱结合水。吸附结合水不传递静水压力，具有一定的黏滞

性和抗剪强度，在高液限土路基湿度平衡后相对稳定。

3.7

路基刚度补偿compensationforsubgradestiffness

路基某层位顶面模量较小时，为了达到路基顶面设计模量的要求，在该层位顶面铺设高模量材料以

提升路基整体刚度的方法。

3.8

路基自密沉降subgradesettlementduetoself-weight

在自重作用下路基密实而产生的竖向压缩变形。

4符号和缩略语

下列符号和缩略语适用于本文件。

CBR：加州承载比（％）

Gs：土颗粒的比重（无量纲）；

Ip：塑性指数（无量纲）；

K：压实度（％）；

lg：路基顶面验收弯沉值（0.01mm）；

ms：土颗粒的质量（g）；

MR：标准状态下路基动态回弹模量值（MPa）；

w：土的含水率（％）；

wg：吸附结合水含量（％）；

wl：液限（％）；

wopt：最佳含水率（％）；

wp：塑限（％）；

d：干密度（％）；

dmax：最大干密度（％）；

3

we：吸附结合水密度（g/cm）；

3

wt：自由水密度（g/cm）；

ωc：稠度（无量纲）。

5勘察

5.1一般规定

5.1.1工程地质勘察应符合JTGC20相关要求，查明高液限土的类型、成因、状态、结构、分布等地

质特征和物理力学特性。

5.1.2初步勘察应基本查明公路沿线及各类构造物建设场地的工程地质条件，工程地质勘察应采用资

料收集、调绘、勘探、原位测试及室内试验相结合的方法，按照公路建设各阶段要求，结合现场地形地

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质条件、填方与挖方路基边坡高度、结构物设置情况等，合理确定勘察方法和工作量。

5.1.3高液限土场地的复杂程度，宜根据表1确定。

表1高液限土场地复杂程度

场地类别岩土组成与结构不良地质地下水条件

地基压缩层或边坡开挖范围内为单无地表水汇集，地下水位埋

简单无土洞、岩溶、滑坡等不良地质

一均质土层深很深，无地下水活动

地基压缩层或边坡开挖范围内为岩发育有土洞、岩溶、滑坡等不良地

汇水面积小，地下水位埋深

较复杂石和土组成，无软弱夹层和外倾结质，但埋深较大，可能影响路基或

较大，水位波动较大

构面边坡稳定

地基压缩层或边坡开挖范围内为岩发育有土洞、岩溶、滑坡等不良地

汇水面积大，地下水位埋深

复杂石和多层土组成，且有软弱夹层或质，溶洞顶板厚度不够，对路基或

浅，地下水活动频繁

外倾结构面边坡稳定影响大

注：任意一项与表中描述相符时，即划归为该类；从复杂开始，向较复杂、简单推定，以最先满足的为准。

5.2初步勘察

5.2.1初步勘察应通过工程地质调绘、勘探和室内试验，并结合附录A查明路线走廊带范围内的高液

限土的分布情况、工程地质条件和水文地质条件。

5.2.2初步勘察应基本查明以下内容：

a）地形地貌条件，如自然坡度、植被发育情况等；

b）高液限土成因、类型、厚度、分布范围、土体结构、分带特性；

c）下伏基岩的接触面形态、岩性、风化程度以及软弱夹层的分布情况；

d）裂隙的密度、深度、延伸方向和发育规律，高液限土的物理力学性质、地基承载力；

e）地表水的汇集和排泄条件，地下水的类型、埋深和水位变化幅度和趋势；

f）土洞、岩溶、滑坡等不良地质的发育情况；

g）既有公路及建筑物的使用情况。

5.2.3工程地质调绘宜沿拟定的路线及其两侧各宽150m～200m的带状范围进行，平面测绘比例尺宜

为1∶2000。

5.2.4工程地质勘探应采用挖探、钻探或物探相结合的综合勘探方法进行。勘探工作量应在工程地质

调绘的基础上，结合场地类别和公路等级确定。

5.2.5高液限土一般路基初步勘察勘探点宜沿路基中线布置，间距及深度应符合表2的规定。每个地

貌单元的勘探点数量不宜少于2个。

表2勘探点间距及深度

场地类别公路等级勘探点间距（m）覆盖层勘探深度

高速公路、一级公路500～700

简单不小于地表以下5m

二级及以下公路1000～1500

高速公路、一级公路300～500

较复杂

二级及以下公路700～1000填方：不小于地表以下8m

高速公路、一级公路100～300挖方：不小于边坡最大开挖深度

复杂

二级及以下公路500～700

5.2.6陡坡路堤或填土高度大于10m的路堤初步勘察应根据现场地形条件、路基填筑高度，布置横向

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勘探断面，其数量不应低于表3的规定。每条横向勘探断面上的钻孔或探坑（井）数量不应少于2个；

控制性钻孔勘探深度不应小于地表以下8m或达地基持力层以下3m，并应满足沉降及稳定计算要求；

当勘探深度内土层下伏分布有土洞时勘探孔应深入洞底完整地层3m～5m。

表3陡坡路堤或填土高度大于10m的路堤横向勘探断面布置数量

场地类别公路等级断面数量（个）

高速公路、一级公路1

简单

二级及以下公路[1]

较复杂、高速公路、一级公路1～2

复杂二级及以下公路1

注：[]表示视需要选做。

5.2.7挖方深度大于10m的路堑初步勘察应根据斜坡的地质结构、水文地质条件和拟定的工程方案，

选择代表性位置布置横向勘探断面，断面数量不应低于表4的规定。每条横向勘探断面上的钻孔或探坑

（井）数量不应少于2个；控制性钻孔勘探深度不应小于路基设计高程以下8m或达地基持力层以下

3m；当土层下伏分布有土洞时，勘探孔应深入洞底完整地层3m～5m。

表4挖方深度大于10m的路堑横向勘探断面布置数量

场地类别公路等级断面数量（个）

高速公路、一级公路1

简单

二级及以下公路[1]

较复杂、高速公路、一级公路1～2

复杂二级及以下公路1

注：[]表示视需要选做。

5.2.8支挡工程初步勘察应满足下列要求：

a）应结合高路堤、陡坡路堤及深路堑等初步勘察工作进行，根据高液限土场地的地形地质条件和

支挡工程的类型、规模确定代表性勘探断面的数量和位置，初步查明支挡地段边坡及地基的工

程地质条件；

b）每个勘探断面上勘探点的数量不应少于2个；

c）支挡结构为圬工挡土墙时，勘探孔应深至挡墙基础底面以下不小于5m；支挡结构采用桩基时，

勘探孔应深至持力层顶面以下不小于5m。

5.2.9高液限土取样应满足下列要求：

a）在探坑（井）或钻孔中采集原状样，应采取边进尺边取土的方法，采集的原状样应密封，避免

湿度变化和扰动，并尽快试验；

b）原状样的采集应从地面以下1.0m开始至勘探最大深度处，大气显著影响层深度以内取样竖向

间距不应大于1.0m；大气显著影响层深度以下，取样间距可为1.5m～2.0m。至基岩附近土

质变软或遇地层变化时，应增加取样数量。同一地层的取样数量，不应少于6个。大气显著影

响层深度可取为2.0m。

5.2.10试验项目应根据地层条件和构筑物类型等选择原位测试和室内试验方法，可参照表5确定。

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表5试验项目

工程类型

测试项目

一般路基高路堤陡坡路堤深路堑支挡结构地基路基填料

颗粒分析++++++

天然含水率++++++

密度++++++

液限++++++

塑限++++++

最大干密度（+）----+

最佳含水率（+）----+

CBR（+）----+

黏聚力（+）+++++

内摩擦角（+）+++++

压缩系数+++-++

自由膨胀率（+）（+）（+）（+）（+）（+）

收缩试验（+）（+）（+）（+）（+）（+）

地基承载力（+）（+）-（+）+-

注：“+”为必做项目，“（+）”为选做项目，“-”为不做项目；路基填料的最大干密度与最佳含水率应采用

湿法重型击实试验确定；路堑边坡勘察应进行原状土的饱水快剪强度试验。

5.3详细勘察

5.3.1详细勘察应充分利用初勘资料，以勘探与原位测试为主、辅以地质调查，详细查明高液限土路

段及沿线各类构筑物建设场地的工程地质条件和水文地质条件。

5.3.2详细勘察内容应符合本文件5.2.2的规定。

5.3.3应对初勘工程地质调绘资料进行复核。对于工程地质条件复杂、填挖较大的路段，应结合现场

情况进行必要的补充工程地质调绘。调绘范围宜为路线中线两侧50m～150m，平面测绘比例为1∶500～

1∶2000。

5.3.4一般路基的详细勘察宜沿路基中线布置勘探点，勘探点间距及深度应满足表6的规定。

表6勘探点间距及深度

场地类别公路等级勘探点间距（m）覆盖层勘探深度

高速公路、一级公路300～500

简单不小于地表以下5m

二级及以下公路500～700

高速公路、一级公路100～300

较复杂

二级及以下公路300～500填方：不小于地表以下8m

挖方：不小于边坡最大开

高速公路、一级公路50～100挖深度

复杂

二级及以下公路100～300

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DB43/T2280—2021

5.3.5陡坡路堤或填土高度大于10m的路堤详细勘察应在代表性位置布置横向勘探断面，断面数量不

应低于表7的规定。每条横向勘探断面上的钻孔或探坑（井）数量，简单场地不应少于2个，较复杂场

地不应少于3个，复杂场地不应少于4个。

表7陡坡路堤或填土高度大于10m的路堤横向勘探断面布置数量

场地类别公路等级断面数量（个）

高速公路、一级公路1

简单

二级及以下公路[1]

高速公路、一级公路1～2

较复杂

二级及以下公路1

高速公路、一级公路2～3

复杂

二级及以下公路1～2

注：[]表示视需要选做。

5.3.6挖方深度大于10m的路堑详细勘察应在代表性位置布置横向勘探断面，断面数量不应低于表8

的规定。每条横向勘探断面上的钻孔或探坑（井）数量，简单场地不应少于2个，较复杂场地不应少于

3个，复杂场地不应少于4个。必要时应结合原位测试手段进行综合勘探。对于复杂的残坡积土场地，

宜采用静力触探、旁压试验等查明高液限土力学性质的分带性；对于裂隙发育的复杂场地，宜用现场直

剪试验测试高液限土强度参数。

表8挖方深度大于10m的路堑横向勘探断面布置数量

场地类别公路等级断面数量（个）

高速公路、一级公路1

简单

二级及以下公路[1]